Baby marrows, also known as courgettes or zucchinis, are most rewarding plants for the home vegetable gardener to grow.
The seed germinates easily and the first fruit is ready for picking within 65 days from sowing. The plant itself is also attractive: it has big, hairy leaves and bears and abundance of yellow flowers that are edible. Each plant needs about one square metre of space for growing, which is far less than other creeping or trailing squash. This makes it a more viable option for small vegetable gardens. The yield is regular and prolific so a small family could easily have their needs met by just two plants.
Baby marrows are lovely and crunchy when eaten raw and can be cooked in any and every possible way, either with other ingredients or as a vegetable on their own. It is one of those staple summer vegetables that one should never be without. Their low saturated fat and cholesterol content makes baby marrows an excellent vegetable for low fat diets, but their sodium content is relatively high. They are a good source of B vitamins as well as dietary fibre, vitamin A, vitamin C, vitamin K and minerals.
When to sow
In most areas the sowing window for baby marrow is from August to November, however in the Lowveld and on the KwaZulu-Natal coast one can sow from February to August. Other than the Lowveld and KZN coast, sow from August in warm frost free areas but wait a little longer in cooler areas where there may be a late frost or a cold snap. For an early start sow seed in 10 cm pots and keep the pots in a sunny, sheltered place. By the time the plants are ready for planting out (in about 4 weeks) the weather should have warmed up sufficiently. The earlier you can get the crop going the better because the plants tend to suffer from mildew during the rainy season. This shortens the plants’ productive lifespan unless you can control the mildew.
Full sun and well composted soil that drains well suits the cultivation of baby marrow. An area where there is good air movement will allow the leaves to dry off quickly after watering or rainfall and ensuring there will be sufficient space between plants will also help with air flow around the leaves. Plants that are too close together can create a humid micro climate that makes the leaves susceptible to disease.
Plant seed 7 cm deep, with two seeds per hole for in situ planting but one seed if you are planting in small pots. For those in the ground, once the seeds have germinated and produced one true leaf then cut off the weaker seedling at ground level (rather than pulling it out). Individual seeds should be spaced 50 cm to 1 m apart and the rows 1 m to 1,5 m apart. Keep the soil moist but don’t water heavily until the seed has sprouted.
Baby marrow plants consist of a single thick stem with leaves; the flowers and fruit are borne off the stem. Most are bushy plants that only require a little support but there are some trailing varieties that can be grown up a trellis or tepee. The first flowers are usually male and will not produce fruit, they can be picked for eating and are the nicest of all the squash flowers. The female flowers can be distinguished from the males by the small swelling at their bases.
The plants have a shallow root system and are drought sensitive, so they need plenty of water. They will not flower if there is not enough water, which obviously affects the harvest. The method of watering is very important. Water the plants deeply around the base and not from above so that the leaves remain dry. If they get wet they become susceptible to mildew. A mulch of straw around the plant should help to keep the leaves off the moist soil.
As the plant grows the thickened stem can be slightly supported so that all the new growth is off the ground. Feed twice during the growing season with a potassium rich fertiliser like 3:1:5 (steer clear of a nitrogen rich feed as this produces leaves at the expense of flowers).
Pests and diseases
Once the rains arrive watch out for mildew. Infected plants can be sprayed with a copper based fungicide. Some gardeners have found that an extremely diluted solution of bicarbonate of soda (1 gram to 100 litres of water) is also effective. The hotter the season the more susceptible the plants become to viruses but there is little that can be done about them – that is why it is best to sow early as possible.
Aphids and thrips can damage the young fruit. Use an organic spray containing canola oil that smothers the insects. Grasshoppers and locusts are best removed by hand.
Baby marrows form quickly once the female flower has dropped. Remove the fruit by cutting it off the stem with a sharp knife or kitchen scissors. Don’t twist and pull it off as you could damage the stem. If left on the stem the baby marrows can grow into a large marrow, about 50 cm long, which is how they are eaten in Europe and the Mediterranean. However, the larger the fruit is allowed to grow the less new fruit is produced. For an ongoing harvest it is best to pick when the fruit is about the length and thickness of a finger.
Baby marrows can be stored in a container or plastic bag in the refrigerator for a few days but not much longer as the quality deteriorates. They freeze well if cooked as part of a larger dish, such as ratatouille.
Baby marrow flowers are an absolute delicacy, especially if they are stuffed with ricotta, brie or camembert cheese, dipped in batter and fried lightly.