http://www.soilassociation.org/groworganic/april
Soil Association : April

April in the garden

The next few months are a busy time in the garden and hopefully you re ready for a surge of seed sowing, planting out and harvesting. This is probably your last chance to catch up on all those little things like clearing out the shed, cleaning the greenhouse, emptying the compost heap and getting beds prepared for produce. Get out now and finish these little projects off: you ’ll be thankful for a bit of organisation and routine tidiness before the growing season takes off.

This month almost every outdoor vegetable grown for summer use can be sown in the open although some still need protections from frosts and cold winds. April weather can be unpredictable so, be vigilant and keep young plants watered, protected or both.

Pests and disease

The warmer weather also brings more pests as aphids, slugs, caterpillars and all sorts of other trouble arrive in the garden. Try to be pro-active and plan ahead with pest and disease control before any potential situation becomes epidemic. You’ll probably never achieve total control so accept this and try to reduce the damage whilst still maintaining a healthy, ecological balance. Here are some helpful strategies to try:

  • Look after your soil: it should be well nourished after the winter if you mulched it or grew green manure crops
  • Rotate crops to help reduce build up of soil-borne diseases
  • Use certified virus-free or disease resistant seeds, plants and tubers
  • Growing crops at wider than normal spacing in rows allows plenty of air to circulate between plants
  • Adjust sowing times for some plants: I have a friend who has a fantastic crop of carrots each year because he plants the seedlings out in June, which is after the carrot fly lays its eggs
  • Create habitats for friendly pests, such as flower pots loosely packed with straw for ladybirds and lacewings, log piles for hedgehogs and nesting boxes for birds
  • Try companion planting: chamomile is a good all rounder and chives are great near beetroot, tomatoes and carrot as they deter aphids. French marigolds are useful in greenhouses to deter aphids and garlic has a pungent smell that aphids avoid. Lavender and nasturtium attract many beneficial insects including bees. Parsley attracts bees and hoverflies, and rosemary planted near brassicas deters cabbage moths, bean beetles and carrot flies. Dried lemon balm sprinkled throughout the vegetable beds is said to deter many pests

Maintenance

Green manure crops should all be turned or rotavated into the soil now, beds prepared and seed sown. Don ’t forget to stagger sowing seed for fast maturing crops like lettuce; otherwise you ll end up with a glut. Lettuce and salad leaves don ’t need a separate bed: simply sow in between rows of longer growing period crops. Use cloches and fleece tunnels to protect tender crops and warm soil up before sowing by using plastic sheeting, old newspapers or carpet. The latter two are brilliant to put on land that has been fallow for a while as they shut out the light, ideal for killing off weeds, but you ’ll need to leave them in situ for a while. Covering the ground also keeps moisture in for prepared seed beds.

Firm in any newly planted trees after frosts and winter storms, adjusting tree straps and stakes as required. Wall-trained fruit benefit from a good soak and mulch: the blossom will still need protecting with fleece or old net curtains at night if frosts are predicted. Check wires and supports for raspberries and other cane fruit. You can still prune trained fruit such as fan-trained, espaliers and cordons whilst plants are growing, as this helps maintain size, shape and bud formation. Container plants can be planted, but it s too late for bare-rooted fruit plants to go in now - wait until November.

Sowing

Most outdoor vegetables can be sown outside now although some, such as runner beans, are best sown indoors and transplanted out next month. Plant maincrop potatoes and keep earthing up to create ridges for frost protection.

Seeds that must be in the ground now include:

  • Onions, shallots and garlic
  • Radish
  • Summer spinach
  • Summer cabbage
  • Swede

Philippa Pearson

Philippa Pearson is a professional horticulturist and gardener, and she looks after a large estate in Hertfordshire amongst other projects. A keen and passionate gardener all her life, Philippa lives in rural Cambridgeshire where her ever increasing organically maintained vegetable and fruit garden provide a year round harvest of interesting crops, despite being on heavy clay.