Your vegetable garden in March - Grow Your Own

Things to do in the vegetable garden

• Keep hoeing: As the sowing season is upon us, we must not forget to keep on top of the weeds. Hoe regularly, when weeds are small. Do so on a dry day but collect up the weeds and compost if rain is likely, to prevent re-rooting.
• Sow green manures where soil is bare awaiting tender crops in May/June - Mustard, Phacelia or Tares - if the soil is warm enough. They will provide ground cover for 2-3 months, feed the soil and provide cover for beneficial insects emerging from hibernation.
• Warm soil by placing black or clear plastic sheets, cloches or garden fleece on the soil.

Sowing and Planting

• Sowing and planting out doors

  Organic gardening books
  from Garden Organic -
  available at trade prices

  	The Garden Organic Guide to Growing Vegetables Our price: £5.84
  	Grow Organic Our price: £11.70
  	Encyclopedia of Organic Gardening Our price: £12.34

  More Garden Organic
  books here

  When soil and growing conditions are right, sow early vegetables outdoors. If the grass has started to grow, that's a good sign that the soil is around 5-6 degrees centigrade - warm enough to allow the hardiest seeds to germinate and grow. If you have a heavy clay soil that is slow to warm, wait a few weeks. Seeds sown in too cold or wet a soil are liable to rot and unlikely to thrive

  Sow outdoors Broad beans Early carrots Parsnips Maincrop peas Radish Spinach beet Turnip

  Plant outdoors Asparagus Onion sets Potatoes Shallots Jerusalem Artichokes

• Quick guide to growing potatoes

  
  Potatoes chitting

  Store the seed tubers in a light, cool (10°C), frost free spot and leave them to sprout. This is known as chitting. Egg boxes make good chitting trays. Make sure you put the tubers with the ‘eye’ end (where the sprouts will grow from) upwards.

  Dig in well-rotted manure or garden compost (apply no more than one wheelbarrow-full of well-rotted strawy manure, or two of compost, per 10 sq metres of ground). Plant tubers into trenches or in individual holes, 7-15cm in depth, cover with soil. See spacings below:

  • 1st early – 28-36cm apart, 38-50cm between rows.
  • 2nd early & maincrop – 36-45cm apart, 65-75cm between rows.

  Potato planting can start from mid March in milder areas, where frost is rare. If the soil is slow to warm, wait until April or May, or protect early plantings with fleece or cloches.

  For more information, Garden Organic members can see the following factsheets online:

  • Growing potatoes
  • Growing potatoes in containers
  • Choose the right potato variety for your garden and table

  These are available in the members' area of this website (requires password), non-members can call 024-7630-8215 for copies.

   

• This is a good time of year to prepare asparagus beds if you have not done it already. To prepare the beds dig a trench about 1m (3.5ft) wide and as long as you like and incorporate lots of organic matter such as garden compost or well rotted manure. If you have a clay soil add horticultural grit to improve the drainage. Make the bed slightly higher than the surrounding soil. If you are buying crowns then all male varieties such as 'Lucillus' and 'Dariana' are the heaviest croppers.

  To plant the crowns dig a shallow trench 15cm (8in) and mound up the bottom to make a ridge in the middle of the trench. Place the crowns on top of the ridge 45cm (18in) apart and spread the roots downwards on either side of the ridge. Replace the soil and keep well watered. Do not harvest any spears until the second year and even then only a third of them. True cropping can begin in the third year.

• Sowing in trays and modules to transplant outside

  Raising plants to transplant outdoors (or under cloches or in a greenhouse/ tunnel) gives you a head start on the season. It is simple to provide extra warmth for a few pots and trays of seeds - in a warm room, or on a heated bench for example. But remember - the seedlings that appear will also need some warmth and good light levels.

  
  Kohl Rabi - best sown in
  modules for transplanting
  
  
  Block sown onions

  Sow in trays and modules

  • Baby beetroot M
  • Brussels sprouts - for early crops
  • Kohlrabi M
  • Early cabbage
  • Summer cabbage
  • Early cauliflower
  • Bulb onions
  • Spring onions
  • Tomatoes - for growing in a cold greenhouse or tunnel
  • Lettuce

  M - these plants resent root disturbance and are best raised in module trays only.

  If you are new to growing from seed, check out the information in our Get Started guide to growing from seed (available online to Garden organic members).
  
  Seed sowing modules (plug trays) can be ordered online from the Organic Gardening Catalogue.

• Raising seeds outdoors for transplanting

  An outdoor seedbed can be used to germinate seeds in, before moving them to their permanent growing position and is a good idea for crops that don't mind root disturbance, especially winter brassicas and leeks.

  To make a seed bed:

  
  St Victor leeks with
  attractive blue/purple leaves
  • Choose an area - a corner of your vegetable plot for example
  • Remove weeds and rake soil to a fine ‘tilth'. Disturbing the soil stimulates weed seeds near the surface to germinate.
  • Leave the prepared seed bed for 2-3 weeks, then hoe off the emerging weeds
  • Sow immediately into the prepared, weed free bed. This is often called the ‘stale seed bed' technique.

  Brassicas, Cabbage, Brussel Sprouts, Kale, Broccoli, Cauliflower etc - sow at 4-5 cm x 20 cm (2in x 8in)

  Leeks - sow at 2.5 x 15cm (1in x 6in)

  To help the soil warm up more quickly, pull back any organic mulches, then cover with cloches or sheets of clear or black plastic. Put these in place a couple of weeks before sowing.

• Direct sowing under cover

  
  Vegetables in a polytunnel

  Hardy crops that are usually grown outdoors can be sown under cloches or in the soil beds of a greenhouse or polytunnel. They will romp ahead and give welcome fresh produce at a lean time of year.

  Sow under cover

  • Lettuce - loose-leaf or seedling varieties are best
  • Kohl Rabi
  • Radish
  
  Cloches available from the
  Organic Gardening catalogue
  • Rocket
  • Baby beetroot - use an early variety, resistant to bolting
  • Spinach
  • Salad onions
  • Peas - mangetout or sugar snap are best
  • Potatoes - compact early varieties
  • Globe artichokes

  Unless your greenhouse or polytunnel is frost free you will need to protect tender plants if a frost is forecast. Horticultural fleece, in single, or double or even triple layers works well. Keep a few pieces, cut to suitable lengths, on hand.

Dug in green manures


Raised bed covered with
leafmould. Mulching helps
to suppress weeds and
retain soil moisture

Other jobs

• Top dress" overwintered crops, such as autumn planted onions, broad beans and spring cabbage, to give spring growth a boost. Use a good rich garden compost, well rotted manure or chicken manure pellets.
• Finish digging in overwintered green manures such as grazing rye and winter tares. Remember not to follow rye with a direct sown, small seeded crop such as carrots or parsnips as the decomposing rye foliage can temporarily inhibit germination. Leafy crops such as cabbages and spinach beet do well after tares, thriving on the nitrogen released as the foliage and root nodules decompose.
• It’s not too late to start a compost trench for your runner beans. They benefit from good moisture retentive material at the roots. Dig down to a spades depth, fill the bottom of the trench with raw kitchen peelings, old Brussel Sporut and Broccoli stems, newspaper and cardboard. Cover with soil to deter wildlife from scavenging. Sow runner beans outdoors from mid- May, depending on local temperatures.
• What you feed your vegetable plots with will depend on what you are going to grow next, what was there last, and the basic fertility of your soil. Root crops and legumes (peas and beans) should thrive without any additional feeding. Other crops may benefit from a dressing of manure, well rotted compost or an organic fertiliser. Use compost at a rate of up to 2 wheelbarrow loads per 10square metres, manure at half that rate.
• Don't forget to plan a crop rotation taking into account the fertility of your plot. See our factsheet, crop rotation (Factsheet requires members' password).

Pest watch

Prevention is always better than even an organic cure. Growing a diverse range of plants and flowers amongst the vegetables will attract beneficial predators, such as hoverflies, thus negating the need for sprays. See our organic factsheet: Attracting beneficial insects for more information.

• Check the leaves and stems of vegetables for pests and diseases, at least once a week. Identifying problems before they get out of control will save you a lot of time and trouble. For help with identification, members can send in a sample to our Organic Gardening Advice Service. For more details, go to the Members' Enquiry form in the members area, where you will see a link to the factsheet about sending in samples.
• Dig up any 'volunteer' potato plants growing from tubers left in the ground from last year, they could be carrying the potato blight fungus. Find out more in our potato blight factsheet.
• 
  Slug trap made from
  dairy container
• Bury stems and stumps of overwintered brassicas as soon as they have finished cropping. Bury them in a compost heap, or in a trench in the ground. This will help reduce the population of mealy aphids and whitefly which otherwise would simply move on to your spring planted crops.
• Clear up any plant debris, and remove diseased leaves from overwintered crops; put them on the compost heap.
• Put out slug traps before making new sowings and plantings and maintain them whilst seedlings are vulnerable. Check regularly and keep topped up with bait such as beer or formulated bait available from the Organic Gardening Catalogue.
• Don't plant potatoes into cold, dry soil. The potato shoots are more prone to attack by the fungus, Rhizoctonia solani causing stem canker, in these conditions. Shoots may fail to emerge when attacks are severe.
• The Organic Gardening Catalogue is available on-line at www.OrganicCatalogue.com or you can request a paper copy by ringing 01932 253666. It is worth a good read before you plan your cropping.

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