Growing
Pruning Phormium Isn't Strictly Necessary - But You Can Tidy Them Using These Tips
IN THIS GUIDE When To Prune 1) Remove Damaged Leaves 2) Cut Spent Flowers 3) Divide Large Plants Phormiums are interesting and dramatic foliage plants that can work well in many UK gardens. They can be grown in the ground in an area of sun or partial shade with free-draining soil, but are popular for container growing in the UK. Typically H4 hardy, they may need some winter protection in many parts of the UK, but are generally relatively easy, low-maintenance and trouble-free plants to grow. Phormiums don’t really need to be pruned at all. However, it is generally a good idea to give them a light tidy-up in the spring: Remove any dead or damaged leaves, cutting or pulling them off as close to the base as you can. Cut out any flowering stems if flowers have formed. Don’t prune plants that have become too large – divide them instead. Difficulty Easy Equipment Required Secateurs or gardening knife When To Prune Spring When To Prune The best time for a tidy-up is spring. You might not need to do this every year, but each year, once spring arrives and when the weather is fine, give your plants the once over to see how they have fared over the winter months. Look for any dead leaves and any leaves which have become damaged during winter storms, or due to winter frosts. 1) Remove Damaged Leaves If you spot any leaves that look unhealthy, damaged or dead, simply pull these off, or cut them off as close to the base as possible. Occasionally, you may find that a plant has been severely damaged, most commonly by frost. Unfortunately, plants that have been severely frost-damaged won’t always recover, but it is worth a try to remove all the dead and damaged leaves and take good care of your plants. Over the next few weeks, new growth may well emerge and your plant may begin to return to full health. 2) Cut Spent Flowers If your plant flowered the previous year, there may also be flowering stems to remove. These too you should cut off as low as possible, taking care not to do any damage to healthy surrounding leaves. “For large Phormium tenax, the flower stem can be 2-3m in height and quite thick at the base,” says Master Horticulturist Colin Skelly. “To remove these you will need some loppers or a hand saw. They do break down relatively quickly in a compost heap but cut into short sections for ease of management.” 3) Divide Large Plants Pruning is not the way to reduce a phormium in size. If you have a Phormium that has grown too large for its location in the garden or is getting too big for its container, then you might wonder how to reduce it in size. Potting up may no longer be practical. If so, you can divide the plant. The division will allow you to obtain several smaller plants from one larger one and it will reduce congestion and prevent overcrowding in your garden, helping the health of the original plant as well as propagating more. As you can tell from the above, pruning is not really something to worry about when growing Phormium in your garden, but do stay on top of the tidy-up to keep things looking good.
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Pruning Lily Of The Valley: Removing Dead Foliage Will Only Help Reduce Untidiness
IN THIS GUIDE 1) Deadhead Spent Flower Stalks 2) Keep Tidy Over The Summer 3) Remove Dead Foliage Lily of the valley is an attractive plant commonly found in woodland gardens, though it can be grown in a range of locations – including in pots. This is not a plant that typically requires pruning at all. In fact, it is a low-maintenance plant that generally requires very little care. As long as you grow it in the right spot, in full or partial shade, in moist and reasonably fertile soil, you should find it mostly trouble-free. However, if you are someone who cannot stand untidiness in the garden, you may wish to: Deadhead spent flower stalks, removing these at the base. Trim away any damaged, discoloured or dying leaves from the plants throughout the summer. Remove dead foliage before new growth emerges in spring. Read more on each of these steps below: 1) Deadhead Spent Flower Stalks Some gardeners do choose to deadhead spent flowering stalks after the flowers bloom in spring, in order to encourage new blooms to form and to keep things looking neat. However, the deadheading lily of the valley plants is not necessary, and if you do deadhead, you will miss out on the attractive green then red berries that follow them. “I don’t think that I have ever deadheaded Lily of the Valley due to the resulting loss of the berries later in the season,” shares Colin Skelly, a Master Horticulturist. “I do tend to clear the foliage once it’s died back and put it on the compost heap as it tends to collapse in a slimy heap otherwise.” You also won’t be able to collect seeds from your plants if this is something that you might like to do. 2) Keep Tidy Over The Summer Lily of the valley is usually untroubled by pests and diseases and is a low-maintenance plant. As long as you make sure sufficient moisture is available, the plants should thrive and create good ground cover all summer long. However, if you watch your plants closely, you may observe the odd discoloured or dead leaf. Any damaged leaves can be cut off if you wish to keep things looking lovely, though again, this is usually unnecessary and is merely for cosmetic purposes. 3) Remove Dead Foliage Lily of the valley is a deciduous perennial, and the leaves will die back in autumn, with new growth emerging in spring. You do not really have to remove the dead foliage at all and it is best to leave the faded foliage in place over the winter months as a habitat for wildlife. However, if this bothers you, you can remove unsightly dead leaves over the winter months or in early spring.
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The Ripe Fruit Of Convallaria Majalis Can Be Collected And Sown For New Plants
IN THIS GUIDE 1) Collect The Berries 2) Remove Flesh From The Seeds 3) Prepare Area For Sowing 4) Sow The Seeds 5) Care For Seedlings References Lily of the valley must be handled with care, but this pretty perennial plant looks lovely as ground cover in deep or partial shade. Convallaria majalis is relatively easy to grow from rooted crowns that are readily available from garden centres and plant nurseries, but the division of existing clumps is the easiest way to obtain new plants if you already have some in your garden. However, if you are patient, you may also like to consider trying to grow lily of the valley from seed. To grow this plant from seed: Collect the ripe fruits with the seeds inside. Separate the seeds from the flesh. Prepare an area in a cold frame or another cool but protected area for sowing. Sow the seeds right away, around 0.5cm deep. Care for the tender young plants, keeping them moist and protecting them from pests. They will typically not flower for several years. Difficulty Medium Equipment Required Seeds, seed bed, cold frame, gardening gloves 1) Collect The Berries First and foremost, it is vital to remember you must wear gloves when handling this plant.1 Lily of the valley flowers will be followed by berries. The berries will start out green, then turn red, then eventually, once the seeds have fully matured, will shrivel and dry and turn reddish-brown. A range of wildlife will eat the berries, so to make sure that they can reach maturity, you may need to cover them with mesh bags before you are ready to collect the seeds. The berries must be fully mature in order for the seeds inside to be viable. 2) Remove Flesh From The Seeds Once you have successfully collected fully ripe berries from your lily of the valley plant, you need to soak the berries in warm water to soften them up, then carefully pare away the flesh from the berries to reveal the 1-3 seeds inside each pod. The seeds do not store well, so you should aim to sow them as quickly as possible after you have undertaken this step. 3) Prepare Area For Sowing It is a good idea to prepare a seed bed in a cold frame in which to sow your seeds. Make sure that the soil is at least 15cm deep and is amended with plenty of organic matter. Ensure that the bed is weed free and raked to a fine, smooth tilth. 4) Sow The Seeds Sow the Convallaria majalis seeds around 0.5cm deep, firming the soil over them. Make sure that the soil is moderately moist, but also that excess water can drain away reasonably freely. 5) Care For Seedlings Germination is not guaranteed, even with viable seeds. However, young plants should appear within a couple of weeks. Make sure you keep up to watering regularly over the summer months and continue to care for your young plants over the next few years. The plants must also be protected from pests – especially early in their lives when they are particularly vulnerable. You will have to be patient as it will usually be a few years before lily of the valley plants grown from seed will flower. “I have never sown Lily of the Valley seed as it tends to spread readily and quickly enough by rhizomes,” shares Horticultural Consultant Colin Skelly. “However, if you wanted to plant up a large area this would be a good option.” References 1. Guide to Poisonous Plants –. (n.d.). Colorado State University. Retrieved March 21, 2023, from https://csuvth.colostate.edu/poisonous_plants/Plants/Details/123
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Lily Of The Valley Is Particularly Suited To Growing In Pots - They Help Control Its Spread
IN THIS GUIDE Suitable Containers Sourcing Compost Potting Up Ongoing Container Care If you are considering growing lily of the valley, in the right situations, it could be an attractive plant to grow in a wide range of gardens. Lily of the valley is a woodland plant, commonly grown as ground cover under trees in a reasonably moist area of deep or partial shade. However, even if you do not have much space, you can still grow this spreading plant in containers. You might do so to contain its spread, or simply because you only have room for a small container garden. “Growing Lily of the Valley in containers is a great option for following on from early spring bulbs in pots or even for including in a lasagne planting scheme with successional spring bulbs,” shares Master Horticulturist Colin Skelly. “Just make sure to locate and reuse the rhizomes when repotting.” Since the plant has a pleasing fragrance, growing it in containers also means that you can move it around to enjoy the smell. Suitable Containers When choosing a container for lily of the valley plants, note that you will usually need a container that has sufficient depth to accommodate the root system of the plant. Choose a container that has enough room for the crown or rhizome you have purchased or for the young plant you may have purchased/moved. Sourcing Compost A standard peat-free multipurpose compost or a homemade equivalent will be fine for growing lily of the valley in pots. The medium you choose should have plenty of organic matter for moisture retention and fertility. Potting Up Rhizomes can be placed into individual pots 8-9cm across or spaced around 2.5-5cm apart in a larger container. If you are planting lily of the valley rhizomes purchased from a garden centre or plant nursery, you should just cover the top of the buds with soil. You can trim the roots a little to fit them into a container, though it is best to keep trimming to a minimum. Don’t cut off more than 10cm or so at most. How Many Can You Plant Per Pot? How many you can plant per pot will of course depend on the size of the crown or offset you are planting, and the size of the container. Remember, these will spread over time but can be divided later. Another thing to consider is planting lilies of the valley in mixed container displays alongside other woodland plants. You might consider planting these with other spring woodland plants, such as bulbs like snowdrops or English bluebells, as well as other plants that like shaded and moist conditions. Ongoing Container Care Convallaria majalis is a pretty straightforward plant to care for – even when being grown in pots. Some key rules to follow are: Place containers in deep shade, partial shade or dappled shade, in a sheltered spot. Keep the plants well watered during dry spells, especially through summer. Remember that plants in containers typically need to be watered more than those in the ground. Enjoy the fragrant flowers in spring, and berries in summer. Mulch around the top of the containers with leaf mould in autumn. In essence, you should look to try and replicate the woodland environment these plants are typically found in.
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Perennial Erysimum Can Be Propagated Very Easily From Cuttings - Here's How
IN THIS GUIDE 1) Select Shoots 2) Take Cuttings 3) Remove Lower Leaves 4) Use Hormone Rooting Powder 5) Pot Up Cuttings 6) Grow Cuttings In Individual Pots 7) Plant Out Erysimum, also known as a wallflower, can be perennial, biennial or annual, and, as a varied genus, these flowers can work well in many different settings. They are typically fairly hardy, preferring well-drained soil and full sun, though they can cope with partial shade. The good news for those who wish to grow perennial Erysimum is that they can be propagated very easily from cuttings. Cuttings should be taken in the spring, ideally in May or June. Here is the process to follow if you wish to undertake this simple garden job: Select a healthy non-flowering shoot. Take cuttings of your perennial Erysimum. Remove all lower leaves from your cuttings. Dip the end of the cutting in rooting hormone (optional). Pot up your cuttings and wait for rooting to occur. Grow on your cuttings in individual pots. Plant out when well established. This process is explained in a little more detail below. Difficulty Easy Equipment Required Gardening knife, cuttings, compost mix, pots, rooting powder (optional) When To Take Cuttings May-June 1) Select Shoots Select an existing perennial Erysimum from which you would like to take your cuttings. Take a good look at the plant and select some healthy, non-flowering shoots to use. 2) Take Cuttings Cuttings of around 10cm in length should be taken from each of the healthy, non-flowering shoots that you have selected. It is best to always take a few cuttings so that you have a better chance of success. Rather than simply cutting off the shoots, it can be beneficial to pull the cuttings off so that they break off just below a node, or the point where the leaves meet the stem, leaving a small heel. A heel cutting is a cutting with a small sliver of stem attached at the base. They often stand a better chance of rooting successfully. 3) Remove Lower Leaves Next, take your cuttings and carefully remove all of the lower leaves from each stem, leaving just 3-4 leaves on each one. Usually, the bottom half of each cutting should be left free from foliage. 4) Use Hormone Rooting Powder While you can certainly get Erysimum cuttings to root successfully without this step, you can, if you wish, dip the ends of your cuttings into a hormone rooting powder. This is a substance which stimulates root growth and can increase the chances of success. “Hormone rooting powders are generally not required if your cuttings are of good quality, taken at an optimum time of year, struck into a suitable growing medium, and placed into a warm, moist, bright location and covered with clear plastic,” shares Horticultural Consultant Colin Skelly. “Often one or more of these factors might be less than ideal, so rooting powders can help to balance the odds in your favour. “I use hormone-rooting powder for cuttings that aren’t quite textbook in quality, age or health.” 5) Pot Up Cuttings Take your Erysimum cuttings and place them around the edges of a small pot or pots. Insert the cuttings into a moist yet free-draining medium, with sufficient organic content, so that the lowest of the remaining leaves are just above the surface of the medium. Make sure that you space the cuttings so that none of the leaves touches one another. Place the pot or pots into a propagator, or cover them with a plastic bottle or bag, then move them somewhere reasonably warm and bright, but out of direct sunlight. Then, wait for rooting to occur. 6) Grow Cuttings In Individual Pots You will be able to tell when the cuttings have rooted because when you give each one a very gentle pull, it will be held firm in the growing medium. New growth should soon be visible. Once the cuttings have rooted, pot them up into their own individual containers, and grow them on until they reach sufficient size to be planted out. Perennial Erysimum can be planted out at any time throughout the year, but it is best to do so in late spring before the weather grows too warm and dry. 7) Plant Out Once your young Erysimum are ready to plant out, you should choose and prepare a suitable spot in your garden. Of course, a sunny and reasonably free-draining spot is best. However, when choosing a spot to plant out your Erysimum, you should be sure to make reference to the specific type that you are growing, as environmental needs can differ somewhat depending on which specific variety you are dealing with.
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Wallflowers Should Be Pinched Back And Deadheaded When Flowers Fade - Here's How
IN THIS GUIDE 1) Pinch Back Bedding Wallflowers 2) Deadhead When Flowers Fade 3) Prune Perennial Types Erysimum, both bedding and perennial types, can be very easy plants to grow. Often, especially with perennial types, these can be a great low-maintenance choice for your garden. While many people are most familiar with the bedding types, which look wonderful in beds and borders during the early part of the year, perennial types with long flowering periods are also well worth considering, as these often take less work over time. E. x marshallii However, there are certain jobs that you will need to do when caring for both bedding and perennial types of these plants, and pruning is an important factor to consider. Here are the steps you should take to prune your erysimums: Bedding wallflowers should be pinched back to encourage bushiness when young. Deadhead wallflowers regularly when flowers fade. Prune perennial erysimum in October. Read on for a little more information about each of the above. Difficulty Easy Equipment Required Secateurs When To Prune October (as late as November) 1) Pinch Back Bedding Wallflowers To encourage bedding wallflowers to develop more bushy and mounded forms, it is a good idea to take a finger and thumb and nip off the tips while the plants are still young. This can prevent them from becoming leggy and encourage a more pleasing form. 2) Deadhead When Flowers Fade Erysimums make excellent cut flowers, so you may well harvest flowers for use in floral arrangements within your home before they begin to fade. Cut back the stems to use as required, cutting back to the foliage to leave the plants looking good. When any flowers left on the plants do die back, you should cut these off. Again, trim back the stems so that they do not protrude above the foliage. Removing the spent flower blooms will often encourage further flushes of flowers throughout the season. However, remember that certain types will self-seed readily, so where this is desired, of course, you will have to leave the faded flowers for seeds to mature and disperse. 3) Prune Perennial Types Bedding erysimums are, of course, discarded after the flowering period ends, but perennial types can grace your garden over several years, so some pruning can be a good idea. Perennial erysimum like the ever-popular ‘Bowles Mauve’ can have a tendency to become leggy and straggly over time. To keep them looking good and prolong to their lives, it is a good idea to prune these plants lightly in autumn each year. Ideally in October, or sometime between September and November, give perennial erysimums a light trim all over, making sure that you do not cut back into old woodier growth. Be sure to cut off just a couple of centimetres or so, and no more than 5cm of top growth each year. These are not plants which can tolerate hard pruning. After pruning, mulch well with organic matter and the plants should overwinter, regrow, and flower well once more the following season.
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13 Favourite St John's Wort Varieties From This Genus Of 400+ Plants
IN THIS GUIDE 1) H. perforatum 2) H. elodes 3) H. bellum 4) H. calycinum 5) H. forrestii 6) Hypericum ‘Hidcote’ 7) H. hircinum subsp. albimontanum 8) H. kouytchense 9) H. lancasteri 10) H. × moserianum 11) H. olympicum 12) H. olympicum f. uniflorum ‘Citrinum’ 13) H. ‘Rowallane’ Hypericum is a genus of over 400 plants, several of which are native to the UK, but many more of which can work well and thrive in UK gardens. A couple of the best native options are listed below, and we’ll also explore a range of non-native options considered to be good choices for UK gardens. Keep in mind that all of these varieties produce yellow flowers. 1) H. perforatum COMMON NAME(S): perforate St John’s wort HARDINESS RATING: H6 FOLIAGE TYPE: Deciduous FLOWERING SEASON(S): Summer SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH Perhaps the best-known hypericum to UK gardeners is common St John’s wort, H. perforatum – a well-known herb. This upright perennial bears clusters of star-shaped yellow flowers 1.5cm, and larger, across. This UK native is H6 hardy and requires little care and is a great choice for wildlife-friendly gardens, wildflower meadows, and other low-maintenance schemes and, as a wildlife-friendly native plant, it is certainly my number one pick. 2) H. elodes COMMON NAME(S): bog hypericum / marsh St John’s wort HARDINESS RATING: H5 FOLIAGE TYPE: Deciduous FLOWERING SEASON(S): Summer SUNLIGHT: Part shade SOIL PREFERENCE: Loam; any pH Another UK native plant, marsh St John’s wort is another member of this varied genus to consider in a wildlife-friendly native plant garden. Perfect for ponds, bog gardens and stream or pond margins, it will help you create a wildlife pond in your garden. It is evergreen and has delicate yellow flowers. It is always a good idea to choose native aquatic and marginal species, and this is one of a number of good options to consider. 3) H. bellum COMMON NAME(S): Hypericum bellum HARDINESS RATING: H5 FOLIAGE TYPE: Semi-evergreen FLOWERING SEASON(S): Summer / Autumn SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH With golden yellow flowers around 3.5cm across, this semi-evergreen densely-branched shrub grows to around 1m in height. The flowers bloom from early summer and into autumn. Grow in full sun or partial shade in moist but well-drained soil. 4) H. calycinum COMMON NAME(S): rose of Sharon HARDINESS RATING: H5 FOLIAGE TYPE: Evergreen / Semi-evergreen FLOWERING SEASON(S): Summer / Winter FRUIT SEASON(S): Autumn SUNLIGHT: Full sun / Part shade / Full shade SOIL PREFERENCE: All soil types; any pH Also known as the rose of Sharon, this variety is a fast-growing and vigorous ground-cover shrub. It can be evergreen or semi-evergreen, and may or may not keep its dark green leaves throughout the whole of the winter months. It grows to around 60cm tall, and yet can spread to 1.2m or more. It has bright yellow blooms throughout summer and into autumn, and red berries which turn black in autumn. It can grow in a wide range of conditions, including full sun, partial shade, or even deep shade, and is H5 hardy. 5) H. forrestii COMMON NAME(S): forrest St John’s wort HARDINESS RATING: H5 FOLIAGE TYPE: Semi-evergreen FLOWERING SEASON(S): Summer / Autumn SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH Another small, semi-evergreen shrub, this option is notable not only for its saucer-shaped yellow flowers that span 5cm across but also for its foliage which partly turns red and orange in autumn. Grow in full sun or partial shade in reasonably free-draining soil. 6) Hypericum ‘Hidcote’ COMMON NAME(S): St John’s wort ‘Hidcote’ HARDINESS RATING: H5 FOLIAGE TYPE: Semi-evergreen FLOWERING SEASON(S): Summer / Autumn SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH This is an evergreen or semi-evergreen shrub which grows to around 1.2m tall. It has large, cup-shaped yellow blooms around 4-5cm across, which are borne from the middle of summer until the early autumn. Place in full sun or partial shade, in moist but well-drained soil. 7) H. hircinum subsp. albimontanum HARDINESS RATING: H5 FOLIAGE TYPE: Deciduous FLOWERING SEASON(S): Summer SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH Growing around 1m tall, this compact semi-evergreen shrub has leaves which emit a strong odour when crushed. The shrub produces yellow flowers 3cm across, with long, prominent stamens, over the summer months. The leaves are slightly more slender than other species. It likes the same conditions as the other options above and is also H5 hardy. 8) H. kouytchense COMMON NAME(S): large-flowered St John’s wort HARDINESS RATING: H5 FOLIAGE TYPE: Semi-evergreen FLOWERING SEASON(S): Summer / Autumn SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH Also known as large-flowered hypericum or large-flowered St John’s Wort, this small semi-evergreen shrub is distinguished by its large golden-yellow flowers. These grow larger than those of other members of the genus – to around 6cm across. Each flower has long stamens and is followed by attractive red seed capsules in autumn. 9) H. lancasteri COMMON NAME(S): Lancastrian St John’s wort HARDINESS RATING: H5 FOLIAGE TYPE: Deciduous FLOWERING SEASON(S): Summer SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH This is a spreading, deciduous shrub which has bronze young leaves that turn green as they mature. The summer flowers are borne on sprays. Flowers form from conspicuous red-edged calyces opening in a star shape and they are golden yellow and around 6cm across. 10) H. × moserianum COMMON NAME(S): gold flower HARDINESS RATING: H5 FOLIAGE TYPE: Deciduous FLOWERING SEASON(S): Summer / Autumn SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH This is a spreading, dwarf, deciduous shrub which grows less than 50cm high but with double the spread, creating a good ground cover. The plant has arching red stems and golden flowers with red anthers 5cm across. 11) H. olympicum COMMON NAME(S): Mount Olympus St John’s wort HARDINESS RATING: H4 FOLIAGE TYPE: Deciduous FLOWERING SEASON(S): Summer SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH Mount Olympus St John’s Wort is a dwarf, deciduous sub-shrub which grows to around 25cm in height and spreads to around 50cm. It has erect stems, grey-green leaves, and bright yellow flowers around 5cm across borne in small clusters. This variety is H4 hardy and may be a good choice for a rockery. 12) H. olympicum f. uniflorum ‘Citrinum’ COMMON NAME(S): St John’s wort ‘Citrinum’ HARDINESS RATING: H4 FOLIAGE TYPE: Deciduous FLOWERING SEASON(S): Summer SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH This is another low-growing dwarf option. It is also a deciduous dwarf shrub, with upright stems and its flowers, which are a pale lemon yellow colour, are borne in summer and are around 3.5cm across. This option is also H4 hardy. 13) H. ‘Rowallane’ COMMON NAME(S): St John’s wort ‘Rowallane’ HARDINESS RATING: H4 FOLIAGE TYPE: Semi-evergreen FLOWERING SEASON(S): Summer / Autumn SUNLIGHT: Full sun / Part shade SOIL PREFERENCE: All soil types; any pH This hybrid is an upright, medium-sized shrub with arching branches. It is semi-evergreen and produces large flowers that are around 7cm across and are bowl-shaped, with an attractive darker golden hue. Of course, these options are just some of the many hypericums that you could consider growing in your garden. “This guide largely sets out species of Hypericum, but within these species are some fascinating cultivars,” shares Master Horticulturist Peter Lickorish. “H. x moserianum, for example, has a wonderful cultivar ‘Tricolor’. Its leaves are edged in cream and new foliage is flushed pink. “H. calycinum ‘Golden Rule’ has zingy orange-coloured new leaves, which turn golden in spring. Perhaps its name is a reminder of the golden rule for Hypericum: they’ll only give you yellow flowers. “For other colours, look beyond the flowers. H. x inodorum ‘Magical White’ has striking white berries long into the winter months, whilst different species and cultivars will produce inedible berries in pinks, reds or black.”
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Maintenance Pruning Hypericum For Shape And Rejuvenation With Peter Lickorish
IN THIS GUIDE Maintenance Pruning Pruning For Shape Pruning Vigorous Varieties Pruning To Rejuvenate References Hypericum is a varied genus, containing a wide range of different plants. They can be annuals or perennials, shrubs or trees and can be either evergreen or deciduous. Many of the hypericum most commonly grown in UK gardens are shrubs and one of the things to think about when growing shrubs is whether they should be pruned, and if so, how and when. Shrub-type hypericums typically fall into RHS pruning group 8, so they usually require little pruning.1 Most hypericum shrubs will need only a light tidying prune after flowering or a light shear over for improved shaping and regular growth, as Master Horticulturist Peter Lickorish explains: “Hypericum is one of those plants which exemplifies that pruning is a man-made art and as such there is no particular right or wrong approach. “The majority flower on new wood, which means as long as you avoid pruning in the 2-3 months before flowering, you can cut back to achieve what you want from the plant.” Some more vigorous growers, such as Hypericum ‘Hidcote’, can be pruned back harder and old shrubs that need rejuvenation can be cut back hard, close to ground level, in spring. Maintenance Pruning Most hypericum shrubs will only need to be tidied up and given a light prune just after they have finished flowering. Dead, damaged or diseased material should be removed, and you can cut back a little to keep the shrubs in shape and looking good. “Some have a habit of producing odd long, straggly stems, which can be clipped back to retain the overall shape,” shares Master Horticulturist Peter Lickorish. You can also keep the shrubs looking good by removing up to around one-third of the older wood, though this is not essential. After pruning, you should mulch the plants, and consider feeding them with a high-potassium organic fertiliser. Pruning For Shape Certain hypericums are grown as hedging or ground cover and require shaping to create the desired effect. If you are growing your hypericums in this way, it is often a good idea to shear over the plants and prune them a little more deeply to ensure that the right effect is maintained. Pruning Vigorous Varieties Some hypericums are more vigorous growers and require a harder prune, whether or not you wish to keep them a particular size and shape. Cutting these varieties back hard in spring will encourage good new growth as well as keep them attractive and contained. “I do tend to cut my Hypericums fairly hard back in late winter or early spring, creating a framework of woody branches around 30cm high, from which a profusion of lush growth forms,” says Peter. “For ground-cover species, I find cutting stems nearest the edge of the border to ground level, or lifting them, allows those slightly further in to arch over and soften the edge. “Keeping this up regularly is a good way to stop it spilling over paths, whilst looking somewhat natural.” Pruning To Rejuvenate If you have an older hypericum shrub that needs rejuvenation, then don’t be afraid to do something quite drastic. Prune the shrub by cutting it back hard, to just 30cm or so above soil level in the spring. This should encourage it to put on healthy new growth. Though they do not need it often, hypericums in general are tolerant of pruning, and can be hard pruned in spring should they get out of hand. References 1. RHS Pruning groups. (n.d.). Royal Horticultural Society. Retrieved March 20, 2023, from https://www.rhs.org.uk/pruning/rhs-pruning-groups
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Here's How To Fix Creeping Rhizomes, Rust Or Frost Damage On Hypericum
IN THIS GUIDE 1) Creeping Rhizomes 2) Rust 3) Frost Damage Hypericums are very reliable and generally trouble-free plants for UK gardens. St John’s Wort and other annuals, perennials and shrubs in this genus are generally rarely troubled by pests or disease. In fact, they are said to repel certain pest species, and may actually make good companion plants and aid other plants growing close by. 1) Creeping Rhizomes The main problem with these plants is not actually a problem for the plant but rather a problem for the gardener. Once certain members of this genus are placed in your garden, they develop extensive creeping rhizomes which may creep underground and lead to plants popping up where you do not want them. Once in place, these are plants that can be very difficult, if not impossible, to get rid of entirely. St John’s Wort, the well-known herb, is often considered a weed in gardens and it can self-seed readily – not always where you want it. It is very difficult to eradicate it permanently from your garden. Even if you think it’s all gone, seeds can lie dormant in the soil seed bank for years, and germinate once disturbed. If you want to remove unwanted Hypericum, try using a specialised herbicide. 2) Rust The very things that can potentially make more vigorous hypericum a problem for gardeners, their tenacity and propensity to spread, also make these plants extremely resilient. They are hardy, happy in a range of conditions, and rarely troubled by pests and disease problems. Occasionally, some hypericum, such as Rose of Sharon, may be afflicted by rust, which is a fungal disease that causes a spotted yellow or bronze discolouration on the leaves. However, this does not typically have a huge impact on the plants and affected foliage can simply be removed to prevent the problem from spreading. “Having worked in gardens where deer and muntjac hold daily feasts, Hypericum is incredibly useful because it is deer-resistant and is one of the surprisingly few plants I have not known them to touch,” says Peter Lickorish, a Horticultural Consultant. “During propagation, grey mould (Botrytis) can be a problem if there is inadequate airflow or too much moisture. “Cleanly pick or cut off the damage and a few surrounding leaves, if possible, to reduce its spread. Sterilise any equipment used afterwards.” 3) Frost Damage While Hypericum are generally hardy in the UK climate, extremely cold conditions, especially when combined with winds and snow, can lead to frost damage. The leaves may have discolouration and turn brown. However, even larger areas of frost damage die-back will usually not be as big an issue as they appear, and new growth should emerge when conditions improve. “The key is to be patient before pruning later in spring,” shares Peter. “The older growth can act as an insulating blanket to protect more fragile shoots underneath.” Of course, it is important to find the right hypericum for your needs and to understand that this genus has a wide range of different plants. However, many of these will be great choices for a low-maintenance and largely hassle-free UK garden.
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