Sunday 20 January 2019

Don't be caught out by a late cold snap in the garden

Tender vegetables won't survive late frosts, writes Gerry Daly

A late spring frost threatens tender vegetables — still just seedlings and vulnerable to damage
A late spring frost threatens tender vegetables — still just seedlings and vulnerable to damage

Gerry Daly

Tender vegetables. I'm not referring to a plant's eating quality but its lack of hardiness in the face of frost. At this stage, with the way the weather has been, that means a late spring frost when these vegetables are still just seedlings and are at their most vulnerable to damage. The most commonly grown tender vegetables are sweet corn, runner beans, climbing French beans, courgettes, pumpkins and summer and winter squashes. Tomatoes can be considered but need a very good summer to do well, and the same goes for tomato relatives, tomatillo and Cape gooseberry.

Of these crops, sweet corn is far and away the most popular and the most successful, and the two points are linked. Very reliable new varieties of sweet corn have been developed in the last two decades, shortening the period from sowing to picking to only a bit more than four months. The seeds can be sown in individual small pots in a greenhouse or on an indoor window sill in mid-April for planting out in early June, waiting until the danger of a chill night is past. The ideal weather is warm and misty, but watch for slugs. If the weather is too cool or dry, the leaves will show yellow but will green up after a few warm days, and then take off, growing very rapidly.

When planting, line the plants out about 40cm apart in a square or broad rectangular block to facilitate pollination - these wind-pollinated plants scatter pollen from the tops of the shoots down on to the female cob flowers. Dig in plenty of well-rotted compost before planting and water if there is a dry spell of more than five days. Pick the cobs when the tassels are brown and withered, and the cob seeds are milky but still juicy.

Soil preparation is the same for all these crops as they are very fast growers. Sweet corn can be sown directly outdoors in mid-May as can runner beans and climbing French beans, which are very fast-growing and productive. Watch for slugs as the young shoots appear. Courgettes and summer squash are used as immature fruits so they do not need as long a growing period as pumpkins and winter squash, such as butternut squash.

Pumpkins are best started in pots under cover in late April or early May (there's still time) and planted out in early June to avail of the full growing season. It is important to grow these plants without any check or setback due to failed watering, cool nights or being cramped too long in the pot. Pumpkins are easy to grow but need lots of space, and rich soil and feeding, to spread their stems to 3-4m with a big array of leaves to trap sunlight and swell the big fruits.

Courgettes are the easiest, quickly producing flowers on small plants followed by the first fruits. The main threat is mildew which brings growth to a halt, but most modern varieties have some resistance to mildew. Keep taking off the courgettes as they reach usable size, or they will grow on to be large marrows.

Runner beans have never become a staple of Irish vegetable gardens, because they can be disappointing. Our summers tend to be cool and wet, which doesn't suit runner beans very well, because the moisture makes very strong leafy growth and there is not enough sunshine to tip the plants over into flowering and, most importantly, setting pods. Cool, dull weather also causes the flowers to fail to pollinate and they drop off. That said, some years are good, some gardens have better shelter, less rain and more heat, and the plants respond accordingly. Sometimes a very big crop can be obtained, creating storage challenges for your freezer.

Tomatoes grown outdoors can also be affected by weather conditions. They too grow luxuriantly in damp conditions and start to form and ripen fruit after prolonged good weather and in a favourable setting. If the first flowers are not pollinated and the fruit set, the later set fruit may run out of growing time. Tomatoes are susceptible to potato blight which ruins the fruit, and the disease can destroy practically all the tomatoes. But, in a good summer, tomatoes ripened outdoors have excellent flavour. Tomatillos and Cape gooseberries, like tomatoes, are better grown in a greenhouse with the extra sun-heat, but every garden and every year is different!

Gardeners' question tiime

n The gurus of gardening are gathering on June 9 for BBC Radio 4's Gardeners' Question Time, held this year in the beautiful surroundings of Mount Stewart, Co Down. Part of the annual Summer Garden Party, tickets;

Blooming lovely

n Rhododendrons have been looking very well this spring, especially on the good sunny days, that make the flowers sparkle with colour and light. They are a source of delight to those with acid soil to grow them in, those who do not can use pots or specially prepared beds.

Come together, right now

n The Community Gardens Ireland Annual Gathering takes place on May 27 at the WeCreate Centre, Cloughjordan EcoVillage, Co Tipperary, a day packed with information and inspiration to help you progress with your own projects. It will follow the annual Feeding Ourselves conference the day before. More at

Sunday Independent

Editors Choice

Also in Life