Marrow Squash Plant – How To Grow Marrow Vegetables
By: Darcy Larum, Landscape Designer
Plants have a long history of earning regional common names for their physical attributes or unique features. The word “marrow” immediately brings to mind the creamy white, spongy substance inside bones. In gardens in the UK and other countries around the world, “marrow” refers to certain varieties of summer squash, which are called marrow vegetables because their 10- to 12-inch (25-30 cm.) oval shaped fruit contains a creamy white, spongy interior flesh surrounded by a hard but thin skin. Read on for tips on how to grow marrow plants in your garden.
Marrow Squash Plant Info
The vegetable Curcurbita pepo is the variety of squash most commonly called marrow. However, Curcurbita maxima and Curcurbita maschata are similar squash varieties which may be sold under the same common name. They produce medium to large plants that will continually produce new fruits throughout the growing season. The heavy production and compact growth habit of marrow vegetable plants make them ideal size for pocket gardens in smaller landscapes.
Plants mature in 80-100 days. Their fruit can be harvested prematurely and used like zucchini. Marrow vegetables have a rather bland taste on their own, but their marrow-like flesh holds spices, herbs and seasonings well. They also are good accents for other vegetables or meats with strong flavors. They can be roasted, steamed, stuffed, sautéed or prepared in many other ways. Marrow vegetables are not a vitamin rich superfood, but they are packed with potassium.
How to Grow Marrow Vegetables
Growing marrow squash plants requires a site protected from cool winds and rich, moist soil. Young marrow plants can be susceptible to frost damage in spring. Plants can also suffer from wind damage if they are not placed in a sheltered location.
Before planting marrow plants, the soil should be prepared with lots of rich, organic material to help provide nutrients and retain moisture.
Best flower and fruit set is accomplished when planted in full sun and fertilized with a vegetable fertilizer every two weeks. Plants should be watered regularly to maintain moist, but not soggy, soil.
This article was last updated on
According to the Oxford English Dictionary, the first mention of vegetable marrows dates to 1822,  zucchini to 1929,  and courgettes to 1931.  Before the introduction of Cucurbita species from the New World, marrow signified the immature, edible fruits of Lagenaria, a cucurbit gourd of African origin widely grown since Antiquity for eating when immature and for drying as watertight receptacles when grown to maturity.
Marrows are commonly cultivated in the British Isles, and the term "marrow" for the plant and for the fruit is current there, especially for the striped, thicker-skinned cultivar. However, both in North America (since the 1920s) and in Britain (since the 1960s), thinner-skinned immature marrows have gained popularity due to their tender skin and distinct flavour. Hedrick (1928) in his book The vegetables of New York p.50, describes the "English Vegetable Marrow" as "one of the earliest forms of marrow squash grown, but has never been exceedingly popular in this country".
The fashion for eating immature marrows, called in Britain "courgettes", is relatively recent in Britain. Sudell (1966)  does not mention courgettes, although he has a section on "vegetable marrow", noting both trailing (vining) and bush types and saying "cut when young". Witham Fogg (1966)  wrote "Courgettes These are really very tender baby marrows which have long been popular in France. . Cooked and eaten with butter they form a very palatable dish." He devotes a page and a half to (vegetable) marrows and less than half a page to courgettes, which he clearly regards as something new to Britain.
The record for the world's largest marrow is currently being held by William Gibbs who grew his giant from an allotment in North West Leicestershire. It weighed a surprising 128 pounds. Gibbs was regarded [ citation needed ] as a master in his trade but retired from competing after only two years at his peak when his crop was sabotaged by a rival grower. He was not only able to grow the marrows out long but expanded girth by around 415mm from the previous year. Gibbs specialised in marrow growing before moving to the Gladioli (flower) section. [ citation needed ]
Marrows, like zucchini,  are low in food energy (approximately 71 kJ or 17 kcal per 100 g fresh marrow) and contain useful amounts of folate (24 μg/100 g), potassium (261 mg/100 g) and provitamin A (200 IU [10 RAE]/100 g). 
Members of the plant family Cucurbitacea, which includes zucchini, marrows, pumpkins and cucumbers, can contain toxins called cucurbitacins. These are chemically classified as steroids they defend the plants from predators, and have a bitter taste to humans. Cultivated cucurbitaceae are bred for low levels of the toxin and are safe to eat. However, ornamental pumpkins can have high levels of cucurbitacins, and such ornamental plants can cross-fertilise edible cucurbitaceae – any such cross-fertilised seeds used by the gardener for growing food in the following season can therefore potentially produce bitter and toxic fruit. Also, dry weather conditions or irregular watering can stress the plant and favour the production of the toxin, which is not destroyed by cooking.  
In August 2015, a 79-year-old German man and his wife ate a marrow grown by a neighbour. The couple noted the unusually bitter taste. Shortly afterwards they were both admitted to a Heidenheim hospital, apparently with symptoms of a gastrointestinal infection. The woman, who had eaten a smaller portion, survived, while the man died. Toxicological analysis of the meal confirmed the presence of cucurbitacin. 
Summer Squash vs Winter Squash
Sign-up for our Free Weekly Newsletter from the National Gardening Association:
· Gain access to free articles, tips, ideas, pictures and everything gardening
. Every week see the 10 best gardening photos to inspire your gardening projects
Summer squash are harvested young and tender, while the skin is still soft and the squash are solid in the middle. They are eaten raw or cooked. This group will loose their flavour as they mature so it is best to pick when the skin can be easily pierced with your fingernail. They are perishable and need to be refrigerated and used within days of harvesting.
Summer squash includes cylindrical, crookneck, straightneck and scallop types. Cocozelle and cousa are often referred to as vegetable marrow. The little Flying Saucer patty pans (scallop) are fun and easily grown in a large containers. The summer squash can be white, green, yellow and even striped.
Winter squash are harvested in early fall. They should have a hard shell, hollow middle and the flesh is typically dark orange. This group includes acorn, buttercup, butternut, pumpkin, warted, and spaghetti types. They are most often baked and have a higher sugar content than summer squash. Winter squash should be stored in a cool dry area. Concrete floors will make them sweat and rot, so be sure to have a barrier.
Squash are available in bush or vine varieties. You will need a lot of garden space for the vine varieties. I let my spaghetti squash ramble off the retaining wall onto a grassed area. The vine varieties tend to continually produce flowers and you will have fruit at different stages. The bush varieties often have one crop and you may want to seed different crops in 2 week intervals to multiple your harvest times. Bush varieties also do well in container gardening.
Direct sow seeds as directed on the package in warm soil and after any chance of frost. In short growing season areas, you may want to start seeds indoors in 4" or 6" pots a few weeks before planting out.
Squash have male and female flowers. It is the female flowers that produce the squash. The male flowers will out number the females and will have a thinner and longer stem. Male flowers will be located along the length of the vine. The female flowers will be located near the base of the plant and will have a slight bulge at the flower base. Hand pollinating is easy and will increase your crop yield. Pick a male flower and hand pollinate the female blooms to produce your fruit. The male flowers can also be picked for consumption and are cooked a variety of ways.
Cross your fingers to have warm sunny conditions with consistent moisture. Cold wet conditions, hail and early frosts will be detrimental. This past summer, hail wiped out my zucchini in Calgary, but we had a bumper crop of spaghetti squash at our garden in NE Alberta.
My cousin Mike, who also gardens in NE Alberta, had started these butternut early indoors and had a great crop as well.
You will be amazed at the fantastic taste of home grown squash compared to commercial crops available at a grocery store. If you have the gardening space, try some squash this year.
There are many varieties of squash—usually classified as either winter or summer squash—and folks often ask about the difference between the two types, as well as which winter varieties are best to grow. Here’s a quick guide to my favorite winter squash varieties.
This year, we had a bumper crop of winter squash to store (which made up for a poor harvest of summer squash and zucchini). The plants were content to stay in their own bed until the neighboring garlic was harvested in late July.
Then the vines leapt over the path into the empty bed and took off. Even though the bed was covered with straw they managed to put down new roots and made themselves at home. Having twice the space to grow in, they produced twice the crop.
Winter Squash vs. Summer Squash
Summer squash (also known as marrow), is a tender, warm-season vegetable that can be grown throughout North America during the warm, frost-free season. We’re basically talking about zucchini and yellow squash they all taste the same but they grow in different shapes and sizes.
Summer squash is harvested before the rind hardens and the fruit matures (unlike winter squash, which is harvested after the fruit matures). It grows on bush-type plants that do not spread (unlike winter squash, which grow on vines).
Image: Various types of summer squash. Credit: Ivana Lalicki/Shutterstock
Winter squash come from the same family as summer squash—Cucurbita— but branch from there into 4 different species:
- Cucurbita pepo includes acorn, delicata, Connecticut field pumpkin, and spaghetti squash.
- Cucurbita maxima includes banana, buttercup, kabocha, and hubbard squash.
- Cucurbita moschata includes butternut, Long Island cheese pumpkin, and futsu squash.
- Cucurbita argyrosperma includes cushaw squash.
Acorn Squash Stuffed With Sausage and Apple. See the recipe! Photo by Becky Luigart-Stayner.
We have grown many kinds of winter squash over the years—acorn, buttercup, red kuri, black futsu, speckled hound, North Georgia candy roaster, and blue hubbard—but we have found that our favorites are delicata, spaghetti, good old ‘Waltham’ butternut, and ‘Tetsukabuto’ (the Japanese pumpkin).
Delicata gets harvested first and eaten right away. It has such thin, tender skin that it doesn’t keep well but you can eat it skin and all. They are usually gone before the other squashes are even harvested.
Image: Delicata squash. Credit: JackK/Shutterstock
Spaghetti squash is nothing like the other fleshy winter squashes in texture or flavor. Cut in half and roasted or steamed until soft, the inside is stringy—like spaghetti—and can be fluffed up and pulled out of its shell with a fork. Served with fresh tomato sauce, it is guilt-free pasta.
Image: Spaghetti Squash. Credit: VM2002 /Shutterstock
Waltham butternut is an AAS winner from 1970 and an old standby. It has tan skin and a long neck that is solid squash the seed cavity is in the bulbous end. Very sweet and smooth, it is my favorite for steaming and mashing.
Image: Butternut Squash. Credit: Pixabay
‘Tetsukabuto,’ The Japanese Pumpkin
‘Tetsukabuto’ is a hybrid cross between moschata and maxima and it is the best of both worlds, very disease and pest resistant while having incredibly sweet and creamy flesh. It is the longest keeper as well. We have had them last in storage until the next summer. Its vines are such strong growers that they are used as root stock for grafting melons and cucumbers to prevent diseases. It does need a pollinator so it has to be grown with another moschata or maxima in the same vicinity.
No problem for us, since we grow butternut in the same bed with it and both do very well together. Since they are ridged, I have never tried to peel them instead, I just cut them in half and bake with a little bit of water in the pan. They are the best tasting squash I have ever eaten!
Why Should You Eat Winter Squash?
Winter squash should be an important part of your winter diet. They are an excellent source of vitamins A & C, fiber, magnesium, niacin, folate, iron, and potassium. The darker the flesh, the more beta-carotene the squash has to offer.
They can be baked, roasted, steamed, sauteed, mashed, or pureed and put into soup, pasta, pies, breads, and muffins! Try this Squash Risotto that just keeps on going, or these Harvest Squash Rolls which work with any winter squash variety. When shopping, look for a squash that feels heavy and has no soft spots. Make squash a highlight of your winter meal!
What are your favorite varieties of squash to grow? Comment below!