plant it, grow it, eat it
What To Sow | What To Plant | What To Harvest | Jobs To Do
May is a busy time in the vegetable garden. Keeping on top of weeding, watering and thinning will help our seedlings to grow strong. Evening slug patrols will help too!
What seeds can be sown in May?
In May the soil is beginning to warm up although there is still a risk of a late frost in some areas.
So, what can be sown in the garden and indoors in May?
Cabbages, cauliflowers, sprouting broccoli, sprouts, kohl rabi, swedes, turnips and broccoli
Now is your last chance to sow many of your brassica family although you can keep planting kohl rabi, sprouting broccoli and calabrese through until July.
If you want to be harvesting Brussel Sprouts in time for Christmas tthen get them in the ground!
Cabbages and cauliflowers should also be planted before the end of the month.
All brassicas (except spring greens) like a bed that has lots of organic material and will benefit from a natural fertilizer.
They also benefit from crop rotation to prevent soil-borne diseases. It’s best to avoid planting brassicas in the same area for 3 years if possible.
You can sow your brassicas indoors or directly outside if your bed already has space for them. Otherwise plant closer together in a seed bed and transplant them to their final growing position when it becomes available.
Cucumbers, courgettes, pumpkins, and other squashes
Squash and courgette seeds like the soil to be around 21 to 35 degrees Celsius (70- 95 degrees Fahrenheit) so they won’t germinate on a cold windowsill. Sow seeds indoors to increase germination success.
They may still require a heatpad or clear bag over the top to get them warm enough. If they’re not coming up then you can pop your pots in the airing cupboard to warm them up and remove them as soon as the seedling emerge.
Seedlings will be planted out next month when temperatures are consistently warmer and all risk of frost has gone.
Cucumbers on the other hand have a preferred germination temperature of around 16 – 35 degrees Celsius so can be sown outdoors after risk of frost has past.
For a continuous supply of fresh leaves then succession sow salad leaves, lettuces, spinach, swiss chard and oriental leaves like mizuna.
If you want to harvest the entire lettuce (with heart) then you’ll need to sow every 10 -14 days.
However, you can get away with only 4 or 5 sowings by picking only the outside leaves and leaving the plant to grow. To use leaves in this way you can sow seeds indoors in February/March and then outdoors at the end of May/ June and again at the beginning of July.
You’re final sowing will be in early September and will remain undercover for a fresh supply of winter salad leaves.
Maincrop peas, sugar snaps and mangetout
Peas are a cool weather crop so they can withstand some cold temperatures. They will still need covering if frost threatens.
During May you can continue to sow maincrop peas, mangetouts, and sugar snap peas outdoors.
Birds love to eat young shoots so cover with a net to protect them.
French beans and runner beans
These beans are tender crops and are not at all frost hardy so seeds are best sown indoors in early May (end of April) for an early crop.
You can sow one bean per pot 5cm (2in) deep and harden off before planting outside at the end of May/begining of June.
Later sowings can be made directly outdoors.
They will thank you for adding some well-rotted manure to your bed before sowing!
Climbing varieties will crop until September so one sowing is fine. However, dwarf beans will only crop for a few weeks so you’ll need to succession sow to ensure a supply of fresh beans (sow outdoors in June and July, for an early autumn crop).
There is little to be gained from sowing warm-climate plants too early in the year when soil is cold.
Towards the end of May sow sweetcorn seed directly or plant seedlings out when they are around 4-6in (10-15cm) high.
Choose a sheltered and sunny spot and plant in blocks rather than rows for successful pollination.
Carrots, beetroot, parsnips, swedes and turnips
Carrots, beetroot and parsnips can be sown anytime from April to June or July. If the weather is cold then beetroot will benefit from a cover to improve germination rates.
To sow make a shallow drill about 1cm deep and lightly sprinkle seeds in rows that are about 15cm apart.
Beetroot can be multisown in modules to save space.
Root crops prefer a stone free soil so prepare your bed beforehand. Avoid sowing in cold or wet soils as the seed is liable to rot.
You will need to protect against carrot fly by covering in a fine mesh net and only thinning and harvesting your carrots on still days and in the evening as carrot flies are attracted to the smell of disturbed leaves.
Swedes, and turnips are infact brassicas (the cabbage family) so should be planted in the same rotation as them and not returned to the same spot until the fourth year ideally.
You can still plant maincrop potatoes in May. They’ll be ready to harvest around 20 weeks from planting and tend to produce larger potatoes that are ideal for baking and roasting.
Click to download our free printable Gardening Month by Month Gardening Guide.
If you’re wondering what vegetables you can plant in May then read on…
May is a busy time of year in the allotment or vegetable garden as the soil begins to warm up and temperatures become more consistent.
Brussels sprouts, cabbages, sprouting broccoli, kohl rabi and cauliflowers
If the weather is favourable then now is the time to plant out those brassica plants you’ve grown from seed or bought as seedlings.
You’ll need to get most slow-growing brassicas in quickly (like sprouts) although you can keep planting kohl rabi, sprouting broccoli and calabrese through until July.
Brassicas need to be planted in a different place each year to avoid pests and diseases like club root. (This is called crop rotation.)
They can be returned to the same position after 3 years (in the fourth year).
All brassicas (except spring greens) benefit from added organic material and a natural fertilizer and require a big space with well compacted soil around their roots.
Cucumbers, courgettes, pumpkins, and other squashes
Plants can be planted outside when the risk of late frosts have past and the soil is warmer.
Harden plants off by placing outside for longer periods each day for around 2 weeks before planting.
Add plenty of well rotted manure to beds and protect from slugs. (Slug collars and evening slug patrols work for us.)
Be prepared to protect plants with cloches, fleece and/or straw if the weather turns cold.
Continue transplanting your seedlings and protecting from slugs and snails. Cover young seedlings with bottles cut in half or buy slug collars.
Plant mixed salad leavs, lettuces, spinach, swiss chard and oriental leaves like mizuna.
Maincrop peas, sugar snaps and mangetout
Pea seedlings that have been raised indoors or under cover can be hardened off and planted outside in May.
Use canes, sticks, string or netting to provide support for them to climb.
They’ll also benefit from a net to prevent birds from feasting on new shoots.
French beans and runner beans
Tender crops like these will prefer to be planted out when the weather is consistently warmer.
From late May/early June you can transplant your runner beans and French beans outside.
Succession sow dwarf varieties every three weeks until early summer for a constant supply. Non-dwarf varieties will crop until the end of Summer provided you pick them regularly.
Your sweetcorn seedlings can be sown in blocks when frost risk has past. Protect if weather turns cold.
Chillies, and peppers
Both peppers and chillies will do better in a greenhouse but if planting outdoors you can do so now.
Harden plants off and protect if cold.
Root vegetables like carrots and parsnips prefer to be sown directly in their final growing position. See ‘What Seeds To Sow In May‘ for details.
Your multisown beetroots can now be hardened off and transplanted in their clumps.
If you want to propogate globe artichokes then this month is the cut off.
Transplanting young leeks is called “dibbing in”.
To plant leeks you simply make a hole the same size as your leek seeding (around 15-20cm) using a stick or dibber (ours is the end of an old spade pointed on one end).
Make the holes along a row, 15cm apart with 20-30cm between rows or if planting in a block leave 20cm in each direction. The smaller the gap you leave the smaller the leek will grow.
Drop each leek in a hole and water in (fill with water to the brim don’t press soil in). Let the soil fall back in on its own as the leek expands in size.
If you’re planting multi sown leeks then transplant each clump 25cm apart.
May is the time to harden off plants grown under cover and planting them in their final position outdoors.
When planting celery make sure it is hardened off properly before planting as it is liable to bolt and seed if shocked or chilled during transplanting or growth.
You will need to have prepared a bed for your celery by digging a 35-50cm wide by 30cm deep trench in October, November or March and adding well rotted manure.
The celery will be planted in a line along the trench and plants earthed up (mound soil around stems when 30cm tall) in order to blanch stems.
Alternatively choose self blanching celery planted in a block 23cm aparth (9inches) and skip this step.
You’ll need to keep them well watered and never let them dry out.
Rhubarb
In May you can transplant any rhubarb plants you’ve grown from seed.
Strawberries
Strawberries can be planted in May and will benefit from a generous amount of well rotted manure.
In May you can transplant container-grown herbs although you’ll still need to protect more tender herbs like basil.
Sow Maincrop potatoes in trenches, under straw or in towers and tubs this month. They’ll be ready in around 20 weeks.
Unless you have a very warm position and live in a mild part of the country then avoid the temptation to plant tomato plants outside until the end of the month.
Even then many varieties will perform better undrr cover especially if you are in a cooler part of the country and have heavy rainful.
Click to download our free printable Gardening Month by Month Gardening Guide.
In May you’ll be using up vegetables that were planted last year whilst also enjoying fast growing crops that were planted in early Spring.
We have listed more of our favourite edible thinnings here!
What are favourite crops to harvest in May?
A helpful guide to vegetable garden and allotment jobs in May.
If you’re relatively new to gardening then it can be helpful to have a clear idea of what needs doing in the garden every month…so here’s our to do list for May…
With the soil warming up nicely May is a good month to get some more seeds in the ground.
Although most of your hardy vegetables will have already been sown you can still make successive sowings of some for a continuous supply.
Beetroots, late peas, carrots, spring onions, spinach, swedes and turnips can all be sown directly in the ground…there are loads of tasty vegetables that can be sown now.
You can also sow cabbages and cauliflowers for Autumn, Winter and Spring either in pots or trays or in a seedbed outside.
Frost sensitive crops should still be sown under glass if it’s cold.
French beans, cucumbers, courgettes, marrows, pumpkins, squash and sweetcorn are all fast growing so sow seeds when date of last frost is no more than 6 weeks away.
Read ‘What seeds can be sown in May‘ for a full list.
Some seeds that have already been sowed may now need thinning out.
Thinning out allows plants enough room to grow properly.
Remember that many thinnings are also edible. For example, beetroot leaves are lovely in salad as are baby lettuce leaves.
When seeds have been planted in pots or trays indoors or under cover they need to be ‘hardened off’ before planting outside.
This process gives them a chance to acclimatize to lower temperatures slowly so that they don’t suffer as a result of the sudden shock.
As the weather improves, move them outside during the day and back indoors at night for around 2 weeks. If they are in coldframes just open the lid during the day.
Brussel sprouts, summer calabrese, cauliflowers and cabbages will all benefit from early planting out.
Check our vegetable planting in May guide to see what’s ready to be hardened off and planted out.
Tender plants like peppers and tomatoes can be planted out in a greenhouse or polytunnel now.
There is still time to sow seeds that should have been sown earlier. Whether you forgot or they got eaten it’s well worth another try.
Seedlings will inevitably catch up with earlier sown seeds because the weather is more favourable.
This time if year, the weather can be even more erratic than usual so keep an eye on forecasts.
Water well and often and don’t let seeds or new plants dry out as their roots aren’t yet established.
Weeds will compete with our vegetables for space, nutrients and water so it’s a good idea to get into the habit of regular weeding.
Hoe between roes and plants once a week when weeds are small and give up the fight more easily.
Choose a sunny day so the weeds dry up on the surface of the soil.
Put mulch down wherever possible to prevent weeds from growing at all…you can use well-rotted wood chip, straw or grass clippings.
Read our top 10 weeding tips here.
When the weather is forecast to drop below 4 degrees Celsius then it’s time to cover tender crops.
We use an insulated picnic blanket to protect our coldframe on particularly cold nights too.
You can use fleece, tunnels, bottles or straw to protect plants.
Some of your seedlings will be looking rather crammed in their pots by now and may need potting on if they aren’t ready to go outside yet.
Re-pot them into larger containers so that they can continue to thrive.
Larger plants that go outside later will benefit particularly from this e.g. courgettes, pumpkins, squash, tomatoes.
Peas and broad beans will need supports to grow so they don’t get tangled on the ground.
You can use hazel or birch sticks or buy canes or chicken wire.
We earth-up potatoes by covering the shoots (often with soil) to prevent the sunshine from reaching the potatoes and turning them green (green potatoes are actually toxic).
Regularly draw up the soil around the plants (every 2 or 3 weeks) to encourage a good crop of healthy potatoes. You don’t have to completely cover shoots once the risk of frost has past.
Amy is on a mission to demonstrate that gardening doesn’t have to be complicated. Her motto is ‘shove it in the soil and see…and usually it works