Gardening Month by Month

May in the Garden

‘A gardener should be a sort of prophet, in foreseeing what will happen under certain circumstances, and wisely cautious to provide by the most reasonable means, against contingencies.'
From The Dictionary of Daily Wants (1858)

Fending off the Frost

For centuries gardeners and farmers had to plan when to sow seeds, when to transplant, how to deal with pests and when to reap their harvest. That's as true now in the age of climate change as it was 150 years ago when the quote above was written. One of the most important events in the gardening calendar that the gardener has to attempt to predict is when the last frost will come. This is the point when the tender plants can be brought out and safely planted in the ground. Do this too early and unprotected plants will run the risk of death if Jack Frost catches them. Wait too long and you miss out on valuable growing time outside.

In the UK, the last frost usually happens sometime from mid-April to late May. When this is exactly depends partly on how far north or south you live (Cornwall is likely to have its last frost some time before Inverness in most years), partly on whether you live in the middle of a city or in the country (cities tend to be warmer than rural areas), whether your plot is in a ‘frost pocket' and what the current weather conditions are like this year. I'm writing this in early April, so I'm afraid my crystal ball is a bit foggy still - you'll just need to keep an eye on the local weather forecast I'm afraid! However even the best gardeners can be caught out by unexpected changes in the weather - even more so now than 150 years ago thanks to climate change induced weather patterns.

However, our Victorian ancestors came up with some neat tricks for dealing with frosts. One of these is the cloche. These were bell-shaped glass domes that gardeners could quickly put over tender plants that would protect them from light frosts. You can still buy glass cloches but, whilst they are rather attractive, they are also rather expensive. Luckily those of us looking to reuse and recycle can make cloches on the cheap from plastic drinks bottles. These will work just as well as the glass ones, are much lighter to move around, are less likely to break and, best of all, can be had for free. A few bottles cut in half and whipped out on unexpectedly cool evenings can help those tender transplants to survive early morning freezing temperatures. If you can get large family size drinks bottles or old ‘water cooler' bottles you can even protect reasonably large plants.

The Victorians were also heavy users of cold frames. A cold frame is just a box with a clear glass or plastic top that acts rather like a giant cloche. You can use it to protect tender plants from frosts, help germinate seeds and ‘harden off' seedlings. Hardening off is simply the process of slowly acclimatising plants to the rigours of the outside world. If a plant has been raised from seed in the warmth indoors it is likely to find the cooler nights outside, even if there is no frost, a bit of a shock. The cold frame gives the plant some protection and allows the gardener to gradually increase the length of exposure to outside weather by slowly increasing the amount by which the glass top is left open.

A last trick that has been used over the years by gardeners is my favourite: ‘hedging your bets'. Let's say you've raised 20 tender little plants that you've hardened off and you reckon the last frost has happened. Some folk will take all 20 plants and have a single transplanting session. This saves them time but if a sneaky late last frost turns up, they could lose all their plants if they can't protect them. If on the other hand you transplant 10 of the plants into the ground and keep 10 under glass or indoors for a week or two more, you'll still have half your crop available if a delayed cold snap occurs, plus you'll potentially stagger the growth of the plants which may help with successional cropping later in the summer.

Fending off the Pests

Anyway, apart from frosts what else should we be looking at in the garden? Well, pests may be starting to appear in larger numbers. Slugs and snails are usually top of the list of most gardeners' public enemies so keep an eye out for them lurking under stones, mulching sheets and other shady corners. And don't just throw them over the fence - not only is this not terribly neighbourly but it also will not stop the little blighters crawling back to your plot under cover of darkness. Either you need to ‘dispatch' them (scissors are quick!) or, if you can't bring yourself to kill them, you'll need to remove them to an area some distance away. You can also try protecting your plants with barriers made of copper, soot, egg shells or sharp sand.

Another pest that can start to appear around late spring/early summer is the carrot root fly. These are low-flying insects that home in on the smell of carrots and lay their eggs around the plants. The resulting grubs eat into the carrots and can ruin an entire crop. Sowings of carrots made a month or two previously will need to be thinned around now, and the smell of the thinned carrots can attract these flies. You can improve your chances by doing thinning on damp evenings when the flies are less likely to be on the wing, covering the carrot rows with fleece (with the edges buried so the flies can't get underneath it), mulching round the carrots with a layer of grass clippings and/or surrounding the carrot beds with a physical barrier a foot or two high (as the flies aren't actually terribly good fliers and so can't get over such low barriers very easily).

Sowing

There's plenty that can be sown now as well. Dwarf French beans can be sown directly outside, as can beetroot, carrots, lettuce, peas, radishes, spinach, rocket, broccoli and cauliflowers. Under glass you can sow cucumbers, courgettes and runner beans (in fact the latter could go straight into the ground towards the end of the month). Herbs such as chervil, dill, fennel, hyssop, parsley and basil can also be sown this month. Brussels sprouts, cabbage and cauliflower plants can be transplanted outside now. Potatoes that went into the ground back in March are likely to need earthing up now as well - this just means scraping some soil up with a spade or hoe over the plants to help keep the light away from the tubers that will soon be developing underground. You can also mulch around the potatoes with fresh grass clippings from the lawn - that will also help exclude the light as well as keeping the weeds down.

And finally, talking of weeds, the warmer weather this month will see them really spring into growth. If you've only got 10 or 15 minutes to spare at your plot, a good way to spend it is to do a spot of weeding. Either hoe them off between rows with a nice sharp hoe or sit down and hand weed around your plants. Then get some mulch down so that you don't have to do it again in a couple of days' time!

Jim'll

photos (c) Salena Walker 2009