Things to do on the plot May

Written by Behemoth

Get growing and finish sowing but watch out for late frosts, says Behemoth in this month's guide to what to do on your patch.

Summer is coming, the soil is warming, seeds will germinate and quickly, early sowings should now be looking good.

But at this time of year you can still get a night-time frost. Frosts are usually over by early May in Southern England, mid to late May in the Midlands and late May in North of England. Here in Leeds I am normally safe by mid May, but more rural or elevated areas may have later frosts. Also, low overnight temperatures may inhibit growth.

General Tasks

Weeeeeeeeeeeeeed! Get that hoe out and keep them down. Ideally do this in the morning so that the sun shrivels and dries out the uprooted weeds and they don’t re-establish, but do it when you can.

Slugs and snails may be emerging. You can lay a trap. Simply put the odd brick or old tile around your plot to give them somewhere to shelter. Then in the morning have an inspection and get rid of them.

Erect your bean supports - wigwams, scaffolds etc. Make sure they are stout enough to take the weight of wet plants in a strong wind.

Thin earlier spring sowings in seed beds – mainly your brassicas but don’t forget lettuces and radishes.

Prick out seedlings sown in April – outdoor tomatoes, sweet and chilli peppers, lettuce, courgettes, marrows, pumpkins, celery, celeriac, cardoons, globe artichokes and sweetcorn. Prick them out from seed trays to individual pots to allow them to bulk up and develop a good root ball before planting out. It easier to prick them out if you water the trays first. Handle only by the leaves and do not touch the stem.

Harden off indoor sowings in a cold frame, or put them outside during the day and bring them in at night. If a hard frost is predicted protect cold frames with an old blanket.

Outdoors - Sowings

Parsnips, salsify and scorzonera

It isn't too late for these - they can be sown up to mid May.

Carrots

Keep sowing

Beetroot

Keep sowing

French Beans and Runner Beans

Can be sown direct in early May if your last frosts have passed by mid May. You might get better success sowing in pots or root trainers. If your frosts continue into late May/early June, consider sowing beans in pots in a cold frame.

Climbing and Runner Beans

should be sown in pairs about 5cm (2”) deep at the foot of each cane about 30cm (1’) apart.

Dwarf French beans

Sow these in pairs 8cm (3”) apart, 5cm (2”) deep with 45cm (18”) between rows. Traditionally beans are used as pods before the seeds develop - but why not let some of your plants develop to maturity and harvest dried beans for storage and use in winter stews. Italian Borlotta beans are ideal for this.

Kohl Rabi

Sow 1cm (0.5”) deep in rows 30cm (1’) apart. Protect against flea beetle by covering with fleece or fine mesh until established.

Leeks

Sow individually in pots or cells or into a seed bed. These are good for planting out and on the site of harvested spring cabbages or new potatoes.

Peas and Mangetout

Sow in a 5cm (2”) deep, 10cm (4”) wide drill made with a draw hoe. Plants should wind up about 5cm apart. Consider soaking seed for a few hours or overnight, especially if your soil is dry.

Spinach

Sow 1cm (0.5”) deep in rows 30cm (1”) apart.

Fat hen and orach

can be sown and lightly raked in to spare ground, as they are tolerant, quick to harvest, and liable to self-seed in a helpful (as long as you're not a stickler for a tidy garden) manner. Barely cover the seed and try to provide orach with a sunny spot.

Swiss chard

This goes like the clappers when the soil’s warm - sow 1cm (0.5”) deep in rows 30 to 45cm (1’ to 1.5’) apart

Swedes

Start these off in pots or root trainers, covering two seeds with about 1cm (0.5”) of compost, for transplanting in late June.

Turnips

Sow by early May for tender specimens,1cm (0.5”) deep in rows 30cm (1”) apart

Sweetcorn

Sow outside for a crop to follow on your cold frame sowings of April. Start them in pots or modules, or sow on site any time from Mid may in Southern areas. If you’re doing this in the north, consider sowing an early variety now. Site sowings should be in a block with 30cm (1’) each way between plants, at least 4 x 4 for best pollination. Companion plant each 4x 4 block with a pumpkin.

Herbs

Now’s the time to start the following:

Basil (possibly wait to the end of the month in northern parts)

Fennel

Chervil

Coriander

Dill

Marjoram

Oregano

Summer Purslane

Chervil

Hyssop

Chives

Garlic Chives

Rosemary

Lavender

Lemon Balm

You can start them in a cold frame by sowing seed in small pots of moist compost. Lightly cover with compost or grit. If sowing outdoors, rake a small area to a fine tilth then broadcast the seed and cover with a light layer of compost, 1cm (0.5”) deep.

You can also propagate cuttings off woody herbs such as rosemary, lavender and sage at this time of year. Remove healthy looking sprigs, strip of the lowest 2cm (1”) of leaves and push the stem into a pot of compost. That’s it.

Winter Brassicas

Kale

Winter Cabbages

Savoys

Purple Sprouting Broccoli

Cauliflower

It’s just getting warm and you’re already thinking of cold frosty days and warm fires. But these brassicas take some forward planning! In late May, sow in a seed bed or for better results in pots or modules, 1cm (0.5”) deep.

In the cold frame

Courgettes

marrows

pumpkins and squashes

Put these into 13cm (5”) pots. Sow the seed upright and cover with its own depth of compost. Plant out early June. You could get away with direct sowing outside from mid May onwards (up to north midlands/Yorkshire). Watch closely for slug attack, though.

Undercover

Daytime temperatures may be good in the poly tunnel or greenhouse (if not too hot - ensure good ventilation) but night time temperatures can still drop - sometimes even below freezing. As such, exercise caution when planting out in the border; delay some plants and pot on if necessary to stop roots becoming pot bound or provide night time protection when needed.

Sowings

Much of the month of May is about planting out pot-sown plants but you can still make some sowings to extend your cropping season.

Basil

Sweetcorn

French Beans

Rocket

Cut and come again salad leaves. Be brutal and harvest these regularly Have regular intervals between sowings, and dispose of salad after two cuts.

Outdoor Cucumbers. In a heated propagator until the middle of May.

Planting out

Pumpkin and Sweetcorn. Plant out April sown seedlings.

Aubergine and Peppers. Wait until late May/early June to plant out these need at low temp of no less than 10C (50F).

Plant out Basil as soon as it looks like it's struggling in the pot.

Melons. Plant out at the end of the month with at least 3-4 true leaves and with supports already in position as the plants are ready to take off. Remove the growing point when it reaches the top of your tunnel/glasshouse, and pinch out shoots after they have produced five or so leaves to encourage fruit bearing sideshoots - then get ready to pollinate.

Tomatoes. Plant out now.

Harvesting

You may get your first strawberries and courgettes.

Mangetout will be cropping still.

Baby carrots and early potatoes may be ready to lift.

Fruit

Protect against frost with fleece.

Control weeds.

Watch for and deal with any pests before they get a grip.

De-blossom any perpetual varieties of strawberry until the end of the month.

Thin out gooseberry fruitlets late in the month. It is often said that these can be used for cooking, although the amount of sugar that would be needed to sweeten might outweigh the benefits.

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