Horticulture Magazine

How To Grow Marrows

marrow fruit growing on the stem with yellow flowers blooming

Marrow Overview

Official Plant NameCucurbita Pepo
Common Name(s)Marrows, Courgette, Squash
Plant TypeFruit / Vegetable
Native AreaCultivated
Hardiness RatingH2
ToxicityEdible
FoliageAnnual
FlowersYellow flowers from which fruit form
When To SowApril (Indoors), May, June
Harvesting MonthsJuly, August, September, October
Sunlight

Preferred
Full Sun

Exposure
Sheltered

Size

Height
0.5 – 1M

Spread
1M (or more, depending on variety)

Bloom Time
July – October

Soil

Preferred
Most Fertile Soil Types

Moisture
Moisture retentive

pH
Any

Marrows don’t get enough love, really.

These long, cylindrical vegetables grow large and quickly, and go a surprisingly long way in the kitchen. Their gentle flavour is fairly versatile, lending itself well to roasting, grilling, and various other cooking styles. And to top it off, they’re easy to grow.

a huge marrow fruit growing over the side of a wooden planter
Need a barrow to carry that marrow

If you’ve neglected marrows over the years and want to rectify your oversight, then you’re in the right place. We’ve written this guide to help even the most novice of gardeners to get a bumper crop of marrow growing in their garden. Soon you’ll be inundated with large, healthy veggies just screaming to be brought into your kitchen, hacked to bits, and incorporated into all manner of recipes.

(With that last point in mind, we’ve thrown in a bonus recipe at the end of this guide to get you started!).

What are marrows?

I’ll be honest: If you’d asked me this a few years ago I’d have said “disgusting,” and moved on. I had little time for marrows at that point, seeing them as a bloated and unnecessary addition to any garden. “Why grow marrows, when the space they take up could be put to much better use?” was my thoughts on the matter.

So anti-marrow was I, in fact, that when a friend gave me a marrow she’d grown in her garden, despite my numerous protests that I didn’t want it, didn’t like them, and wouldn’t eat it, I used it as the basis for an experiment instead of eating it. I took it to the top floor of my house, opened the window, dropped it, and watched it fall onto the concrete below.

(Not much of an experiment, I grant you. Good display though!)

wooden table with marrow fruits at various stages of ripeness
Deserving of so much more than a free flight from a third floor window

Now, however, my answer would be a lot more forgiving. Marrows are vegetables closely related to melons, squashes, and pumpkins. They share a similar texture, if not a little squelchier, and have a gentle flavour that acts as a canvas for other flavours to play upon.

Marrows are also very similar to courgettes, which makes sense considering that it’s the same plant. Leave a courgette on the vine for longer and it will keep growing, at some point reaching the right size to be classed as a marrow.

Zucchini is the American word for this vegetable family, and the first recorded use of that term was in 1929. The concept of courgettes came later, with that term first being recorded in 1931.

How to grow and care for marrows

By now you’re probably just wanting to get started with growing your own marrows. This section outlines everything you need to know to do just that. You’ll find information on finding the right spot, planting out, watering and feeding, and protecting from common pests.

Where to grow your plant

Marrows like full sun, moisture-retentive soil, and shelter from the elements. Find a spot that fits these criteria, and you’ll be rewarded with a healthy marrow harvest soon enough.

Sowing

It’s easy to grow marrows from seed, and you can pick up packets from all good garden retailers. You can sow indoors or outdoors, too, giving you flexibility to choose the method best suited to the space and time available.

To sow marrows outdoors, put them about 2.5cm into the ground. We recommend planting 2 or 3 for each plant you want, all in the same hole. Cover each with plastic, netting, a cloche or similar to keep pests away, and aim to leave them undisturbed for a couple of weeks after germination. Before the next step, remove all but the strongest seedling.

Aim to sow outdoors in May or June.

To sow marrows indoors, sow individual seeds about 15mm deep in pots at least 8cm deep. Lay the seeds on their sides. You can do this in April as long as temperatures won’t fall below 18 degrees.

Transplanting into the ground

Marrows need special planting pockets prepared before you plant them out. This involves scooping out about 15 inches squared (width, height, depth) of soil and filling with compost. Do this a couple of weeks before you plan to plant out your marrow seedlings, to ensure the young plant has all the nutrients it needs as soon as it hits the ground.

Make one planting pocket for each plant.

If you sowed your marrow seeds indoors, you’ll need to harden them off before planting out. For one week leave the plants outdoors during the day and bring indoors overnight. Then, the next week, leave outdoors in a very sheltered spot for the whole week. This will get them acclimated to outdoor conditions, without shocking them too much that it’ll cause damage.

If you’re not keen on starting seedlings indoors or outdoors you can buy young marrow plants from garden stores, and these are ready to plant directly into the ground.

Growing marrows in growbags or containers

Marrows also grow well in containers or growbags; just make sure the container is big enough! Diameter and height should be at least 45cm. With growbags, don’t plant more than two marrow seedlings in a bag otherwise it’ll get crowded.

Whatever method you choose, aim to plant out your marrows in May or June.

Watering

These big plants need plenty of water to keep healthy. Take care to water the soil, not the plant, as overly moist conditions topside can lead to damage.

a young squash plant with yellow flowers
Marrows sporting lovely yellow flowers

If possible, dig a small hole next to the marrow, taking care not to damage it, and water into that: This will ensure that the water goes to the roots rather than the parts of the plant just below the soil. Hydrating roots rather than plant material reduces the risk of rot.

Fertilising

Once you spot your first fledgling marrow, feed the plant fortnightly with a liquid fertiliser. Doing so will encourage more growth, giving you bountiful marrows further down the line.

Supporting your marrows

Not many vegetables need this step, so you may not have seen it before. We recommend placing each marrow on a flat surface (like a tile) to keep it away from the soil. This prevents scuffing on the bottom, and should lead to better looking veggies at harvest time.

Harvesting

When the marrow is at the size you want it, simply pluck it from the stem. Marrows are ready to harvest in July and will continue to ripen until October, giving you a long harvest season.

And if you’re not feeling patient, remember you can harvest small marrows as courgettes.

Troubleshooting your crop

Marrows are prone to a few issues, but knowing what you’re up against is usually enough to prevent catastrophe. Here’s what to keep an eye on.

No fruit, or stunted growth

In years with poor weather in the early summer, you may find that your marrows are small or non-existent. This is caused by lack of adequate pollination and will, when the weather gets better, resolve itself. Just be patient and prepare for the eventuality of harvesting a little later than initially planned.

Mould

Sometimes you’ll find blankets of grey mould covering parts of your marrow plant. This is more likely in humid conditions, providing a good reminder of why it’s important to water the roots, rather than the top of the plant.

If you do see mould, remove and destroy the infected areas to prevent the issue spreading elsewhere in the plant.

Our favourite marrow recipe

As mentioned earlier, my relationship with marrows wasn’t always so accommodating. This is the dish that changed my mind. It’s simple, sure, but it gives marrow a chance to shine.

Roasted vegetables, with marrow

It’s not going to win any cooking awards, but my oh my will it taste good. Roasted veggies are simple and delicious, just chop them up, add your favourite seasonings, drizzle with oil, and roast on a high heat.

Roasted or grilled, either will do

Here’s how to do it:

  • Preheat your oven to 200/180 fan.
  • Chop vegetables into chunks. As well as marrows you can use peppers, mushrooms, garlic, onion, sweet potato, aubergine, corn, and many more.
  • Sprinkle seasoning on top. Cayenne or paprika always go down well.
  • Drizzle with olive oil.
  • Shake the tray, making sure that all the veggies are nicely coated in oil. Add more if necessary.
  • Pop into the preheated oven for 45-60 minutes, checking regularly towards the end to make sure you get hit the sweet spot where they’re browned and slightly crunchy, but not burned.
  • Remove from the oven.

On the straight and marrow

Thanks for reading our guide to growing marrows in the UK. Soon you’ll be singing the overdue praises of this currently unsung vegetable, welcoming it into your kitchen and exploring the myriad ways its tender flesh can be used.

And because they’re so enormous and easy to grow, it’s likely you’ll have leftover marrows for friends and family. Just make sure that they’re happy to eat them or, if not, that you’re happy for them to find other uses.

Happy growing!

© 2021 TKO DIGITAL LTD | Registered in England and Wales No. 10866260 | This website uses cookies.