Forsythia

Overview

Official Plant Name	Forsythia
Plant Type	Shrub
Native Area	Mostly East Asia
Hardiness Rating	H5
Toxicity	None
Foliage	Deciduous
Flowers	Tubular bright yellow flowers
When To Sow	March, April, September, October
Flowering Months	March, April, May
When To Prune	May, June

Forsythia Bushes are very popular as they fulfil a dual role. These low-care shrubs are ideal for privacy screens and separation walls from one to three metres tall. They are also high-quality ornamentals, especially through spring when they put on a stunning show with leafless branches bedecked with brilliant yellow bell-like blooms, and to some extent also in autumn with rich fall colours.

Forsythia is a genus of what are technically deciduous shrubs but informally are flowering bushes. Considered an ornamental plant, it is a member of the Oleaceae family which includes Olive Trees, Jasmine, and Lilac. Most species grow from one to three metres tall. While two metres is just about right for privacy screens, taller varieties of Forsythia make very good backdrops for a flower bed or at the far end of your garden, and the smallest varieties are equally good for borders.

The principal attraction of this bush is the profusion of yellow blooms it starts to wear from early spring, well before it sprouts leaves. As a result, one sees a lattice of spreading, rangy, slim, leafless branches covered with an abundance of yellow flowers, which in turn, are often covered with bees and butterflies! 

The flowers’ diameter ranges from two to four centimetres and their colours vary from pale yellow to golden yellow depending on the variety. They have four well-separated lobes and are bell-shaped or trumpet-shaped. As for the leaves, they are mostly ovate, and are usually simple but sometimes lobed.

Just as the spring flowering season ends Forsythia starts to leaf. Thus, a sparkling yellow ‘wall’ becomes deep green and stays that way during summer. Come autumn and there’s a change of colour once again. Depending on the particular Forsythia species, a smaller or greater number of leaves adopt autumn colouration, slightly on most species but radically on a few. Once again depending on the variety, this colouration is in shades of rust, orange, red, bronze, and purple. 

Forsythias retain their foliage all autumn long, if the climate is cooperative, and are one of the last shrubs to shed their leaves.

These no-nonsense bushes are strong and tough, and with next to no care or maintenance you can count on them as a ‘living wall’ to act as a border, backdrop, boundary marker, or privacy screen. 

Background and Origins

Forsythia has quite an interesting distribution. It has eleven species of which ten are native to Southern and Eastern China, Japan, and the Koreas, and only one is native to Europe, specifically Albania and the Carpathians. In China they are found growing wild along streams.

Forsythia have been cultivated in Chinese gardens for centuries; equally, they are a frequent and important element in Japanese Gardens.

Forsythia suspensa was introduced from Japan to Great Britain in the 1850s by way of the Netherlands. At about the same time period Forsythia viridissima was introduced to a few European nations where it caught on as a garden bush. Both these species are native to Southern China.

Forsythia suspensa is also called the ‘Weeping Forsythia’ because of the tendency of its branches and boughs to bow and droop, and sough in the wind. In fact, they are used in European gardens for this very feature where they are trained to ‘weep’ over a boundary wall or a trellis.

The origin of most cultivars is Forsythia x intermedia. This is a hybrid that was the result of combining the above-mentioned two species over a century ago. It bears flowers of a rich yellow hue and bears them more profusely than either of the parent species. This hybrid has an upright habit but with gracefully arching branches. 

Underneath we evaluate an even dozen Forsythia varieties.

Varieties

F. x intermedia ‘Meadowlark’ is an American cultivar. Its deep-yellow flowers fall away earlier than many other species but the buds are hardy down to near-freezing. It is even more pest- and disease-resistant than other Forsythia varieties, and that’s saying something. It reaches a height just shy of 3 metres and has about the same spread, and is a ‘Size Large.’ 

F. x intermedia Week End = ‘Courtalyn’ is a popular and widely-available variety. The branches are stiffly erect. Reaching a height of right around 2 metres and a similar spread, it’s a perfect ‘Size Medium.’ The flowers, at 3 centimetres, are also a ‘Medium’! It blooms profusely through spring. 

F. x intermedia ‘Lynwood Variety’ is another popular and widely-available variety. Its branches too are stiffly erect. Another ‘Medium,’ it reaches a height of 2 to 3 metres while the flowers are closer to 4 centimetres. It is a profuse bloomer and is recognised for its vigour with the RHS’s Award of Garden Merit.

F. Marée d’Or = ‘Courtasol’ is a ‘Size Small,’ reaching only 1 metre in height with a spread up to 1.5 metres. The smallish flowers are a pale bright hue of yellow. It is a profuse bloomer and is noted for being one of the first Forsythia varieties to start blooming, sometimes even from late winter. It too is a recipient of the RHS’s Award of Garden Merit.

F. x intermedia ‘Kolgold’ or ‘Magical Gold’ is another small variety, reaching about 1.5 metres both in height and spread, seldom reaching 2 metres. This relatively new cultivar is a profuse bloomer, producing flowers 2.5 to 3 centimetres across. This variety stands out for the deep golden-yellow hue of its flowers.

F. x intermedia ‘Goldrausch’ is a smallish variety with a height and spread between 1 and 2 metres. Its habit is distinctly fountain-like, so to speak. This German cultivar is notable for its characteristics of producing blooms on old wood, flowering a little later than most other varieties, and also keeping its flowers a little longer. It is one of the most reliable and trouble-free varieties.

F. koreana, as indicated by its name, is a native of Korea. It is a proper ‘Size Large,’ reaching up to 3 metre heights. Its large flowers are a vivid yellow-golden shade but on this species, the foliage is just as showy. The leaves are darker than other varieties and are serrated. Furthermore, they display a striking white ‘latticework’ on their surfaces. And they turn purple from early Autumn!

F. ovata ‘Tetragold’ is a cultivar from the Korean species of Forsythia that grows relatively fast but is a ‘Size Small,’ topping out at 1.5 metres in both height and ‘girth,’ and sometimes less. It has a dense, bushy habit and produces large flowers of a golden-yellow hue. It is one of the earliest varieties to bloom and its buds are also hardier than other varieties.

F. ‘Fiesta’ (v) is one of the more spectacular varieties as the foliage nearly steals the show from Forsythia’s celebrated yellow bells. Another ‘Small’ that also reaches a maximum height and width of 1.5 metres, it has a bushy, mounded shape. The flowers are a deep yellow colour. The leaves have cream and yellow blotches usually at the centres but sometimes at the edges on a brilliant green ground.

F. ‘Show Off Starlet’ does not reach even a metre in height and barely a metre in width so it’s surely an ‘Extra Small.’ In fact, it is a dwarf variety that is dense and bushy. It is a relatively recent American cultivar. The flowers are of a bright yellow hue but it’s their awesome profusion that makes this variety a ‘starlet’ as branches can and do get covered with blooms from end to end.

F. suspensa ‘Nymans’ is also a ‘show-off’ but for entirely different reasons. Usually 3 metres and not infrequently 4 metres tall with a similar ‘girth,’ it’s an ‘Extra Large’! The flowers too are of a stunning size of 4.5 centimetres. While the foliage is dark, the flowers are unusually gentle in both hue and ‘habit:’ they are a soft, pale yellow, and are nodding and pendent. This variety blooms after virtually all other varieties.

F. europaea or Albanian Forsythia, the last species on our list, is also the last Forsythia to start blooming, has a relatively unkempt habit, is probably the least profuse, and certainly has the least showy blooms. As one may expect, it is not very popular. Yet it deserves a mention because it is anamolous in every way, including being unique as the only Forsythia species to be native to Europe. Also, it is becoming quite rare. 

Habitat & Growing Conditions

In general, Forsythias are hardy to USDA Zones 5 to 9, depending on the particular variety.

As most European Forsythia cultivars descend from species that grew and grow wild along streams and waterways in Southern and Eastern China, Japan, and the Koreas, the best growing conditions should mimic their native habitats. So the most suitable climate for Forsythia varies from temperate-warm to cold, the soil needs to be moist but well-drained, and while the aspect may be to any direction the exposure should be full sun or mostly sunny.

They prefer a little moistness in the soil and some moisture in the air; very dry weather conditions affect flowering. They are perfectly content in soil varying from Slightly Acidic to Slightly Alkaline; pH 6.0 to 8.0.

When and Where to Plant Forsythia Bush

Almost all Forsythia are very easy to grow in late summer and early autumn from semi-hardwood (or semi-ripe) cuttings. In late spring they can be grown from greenwood cuttings.

Forsythia may be planted wherever the soil and weather conditions, as outlined above, are suitable. The taller varieties can be planted at the rear of the garden as a backdrop or used as seperation walls and privacy hedges. The shorter varieties are ideal for borders and edges, but also as companion plants in a bed if they are kept pruned. The medium-sized varieties can be used as elements of a formal garden (as they are in Japanese Gardens).

A variety of Weeping Forsythia is perfect for growing on a trellis or for planting right beside a pergola.

Feeding, Care & Growing Tips

Forsythia is a no-fuss plant that demands virtually no feeding or care.

Mature Forsythia bushes have a strong root system and make do with moisture in the soil and water from rainfall. They will also tolerate a period of drought but if you get a prolonged dry spell, it is much better to water them than to rely on their drought-tolerance. Fresh cuttings. layerings, and immature plants should regularly be watered.

What Forsythia can’t do without is ample sun. Though they fare very well (thank you!) in partial shade, this does have a negative impact on flowering. Therefore, full sun is best for this plant, particularly in the United Kingdom.

These bushes will also benefit from an application of fertilizer once at the onset of spring and once more at the beginning of summer. A 20-20-20 fertilizer would be a very good choice. Plants may be fertilized only after they are one year old.

Pruning Forsythia Bush

You don’t have to prune Forsythia; in fact, quite often the more ‘well-bred’ varieties are left unpruned for years. Pruning Forsythia is a question of one’s tastes and needs.

If you want to prune or ‘shape’ your Forsythia, the ideal time to do so is during end of spring and beginning of summer. However, if you want to thin a dense bush, do so in the beginning of spring. Removing or cutting down to the ground about 25 percent of the oldest branches will, both, do away with the parts of the plant that are least productive and stimulate fresh growth.

Common Problems

Forsythia flowers are, fortunately, a hit with butterflies and bees; the buds are, very unfortunately, also a hit with birds, so you may have to watch out for finches, sparrows, and other such naughty birds.

Otherwise, all you need to be concerned about with these pest-resistant plants is Forsythia Gall and Crown Gall. These are bacterial diseases that cause abnormal, tumour-like growths. These diseases can affect any part of the plant and often escape detection and are difficult to diagnose. Very unfortunately, they are contagious and spread via soil. Treating them is best left to a professional arborist.

Where to Buy Forsythia Bush

Quite a selection of Forsythia varieties are sold as bare roots or as potted plants by numerous nurseries in the U.K. They can be bought on site or ordered for home delivery. 

However, you don’t have to buy Forsythia if a friend or a neighbour has a variety you want, or vice versa.

You can start off a new Forsythia plant any time from late spring to early autumn by rooting an appropriately-taken cutting in a rich planting soil that includes peat moss. You will – of course – have to take proper care of the cutting until it is established. 

You could also watch for a branch that has touched the ground and put down roots. Once it has developed into a plant in its own right by putting out shoots and branches, it can be removed and transplanted. Take good care not to damage the tap root.

Finally, if you know the technique of layering, you can get new Forsythia via this fourth option as well.