April allotment garden

Last revised: 09 January 2018

Seasonal reminders, hints and tips.


Near end of April, if ground is not still too wet, sow a crop of peas which should mature in 13 - 15 weeks. Consider successive crops by planning another row in a months time. With good weather you can continue to sow until mid June and get a decent crop at end of September.

Sow seeds in a shallow trench about 2 inches (5cm) deep and 2 or 3 metres long. Water the trench. Scatter seeds about 3 inches (8cm) apart, cover with soil or multi-compost and firm down. You may wish to cover with fleece to prevent birds eating new shoots.

Germination takes about 2 weeks, which you should provide some support for shoots to attach their tendrils. A wide mesh works well, or try thin branches that have plenty of side branches.


Like most seeds and plants, potatoes do not like sitting in water, and unfortunately many plots are affected by this problem. If you were to dig a potato trench below the path level the chances of being too wet are greater during April.

One technique worth trying is to fill the trench with well rotted organic matter, hoeing a deep layer of soil on top, then sow potatoes, will give you a better chance of avoiding rotten seeds. The organic matter will help feed the soil and crop for this year, plus build up the surface level.

An alternate to planting shallow and hoeing up as the potato haulms (leaf and stalk) emerge, is to hoe soil into a mound along the row, cover with black plastic and poke holes in at intervals 15 inches (35 to 40cm) and plant through the cover. This will help warm the soil, supress weeds and keep moisture in.


Harden off seedlings by placing them outside, under cloche or on cooler part of greenhouse where, for a few hours each day, they can acclimatise to outdoors. Be aware of frost and wet conditions. After about 2 weeks the seedlings should be ready to plant out.

Peppers and Chilli

Getting an early start for this crop is essential as they take a long time to mature and the growing season in England is relatively short, cooler and less sunny than the plants would like.

If you have seedlings that are big enough to handle, transplant to larger pots, avoid handling the roots and stem by holding a leaf, which will cause less damage.

One plant per 3 to 4 inch pot of multi-purpose compost should be sufficient. Water in well and keep in a warm sunny place, avoiding the intense heat like radiators or greenhouse heaters. Maintain a damp soil, but not soaking. Try covering a couple of plants with clear plastic bag tried with string or rubber band which can provide a good closed environment for the seedling and water from the bottom.


Indoor or in warm greenhouse, start sweetcorn in deep pots or root trainers. Keep moist, but not wet as seeds have tendency to rot. They need light, but not too warm to avoid bolting. Depending on variety shoots will show in 3 to weeks, after which a regular spray of tepid water is required. At 4 to 6 inches (10 - 15cm) they will be ready to plant out.

Broad beans

Look out for notches on leaves which usually indicates bean weevil, a 3mm grub which will devour a crop very quickly. Best to pinch these off by hand, but a spray blast of soapy water all over the plant will discourage them.


If you have strawberry runners, pot them in 3 or 4 inch pots with multi-purpose compost, keep moist and away from frost. They should be ready to plant out in 3 to 4 weeks.


Cabbage Fly affects all brassica which includes turnip, swede and radish. Signs include leaf discolouration, wilting and lack of vigour. Carefully lift a couple of poorly plants and look for small maggots around the roots. Make sure they are properly drowned or disposed of.

The pupae remain in the soil over winter and emerge as flies when ground warms up, just when we have planted out seedlings. The eggs are laid at base of plants and the maggots will crawl to the roots. The cycle starts again after a month.

Rotate your crops to avoid planting brassica in same place as previous 3 or 4 years.

If not using chemical controls try placing a disc of dark material like plastic or cardboard around the plant stem and pressed firmly to top of soil. A disc about 6 inches (15cm) diameter with central hole of one inch (25mm) and cut on one radius from centre to outer edge.

Carrot fly presents a similar problem to cabbage fly as the pupae overwinter where carrots had been grown previously, and will remain in the ground for more than a year. Once again good crop rotation plays an important role.

For your new crop select a variety that provides a defence against carrot fly and cover the sown area with fleece. You can also mix in spring onions between rows of carrot which disguises the carrot smell.

Other tasks

Keep persisting with removal of weeds. You may see many small weeds appearing which should be hoed off promptly. Larger weeds should be pulled. Simply hoeing the surface disturbs weed roots and discourages establishment and further growth.

A technique worth trying is to drop pulled weeds into a bucket of water, stir off the soil and put weeds onto compost heap. You can leave weeds in the bucket of water for a week, which will weaken or kill them off. The dirty water can be poured onto the plot.