April

Coppice Road Allotments Association

www.poyntonallotmentgardeners.org

(affiliated to the National Society of Allotment and Leisure Gardeners Ltd)

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7 May, 2012

Monthly Gardening Calendar - Reminders

April

Under Warm Glass

There is still time to sow celery, cucumbers, peppers, marrows etc., though heating can be reduced in the warm house over the course of the month, only keeping on if late frost threatens. Many annual half-hardy annual flowering plants can still be sown, or grown on from plug-plant seedlings obtained from garden centres or by mail order.

Continue to prick out and pot on seedlings from earlier sowings.

Under Cool Glass

Tomatoes from earlier sowings will be showing flower colour on the first truss and may be planted out during the second-half of the month in the greenhouse borders or grow bags, tomato rings or large pots. Early flowers may need some help with pollination if insect activity is absent or reduced.

Sowings of lettuce, cabbages, late sprouts and other later maturing brassicas can still be made under cover. If a glasshouse is unavailable, cold frames or cloches may be used.

Vegetable Plot.

If not already done so, first early potatoes should be planted out as early as ground and weather conditions permit, followed by second early potatoes in the first half of the month. Main crop potatoes should be planted in the second half. Potatoes can be planted in deep drills or trenches, or in individual planting holes about 5”deep, to leave 5cm (2in) of soil covering them. Potatoes may also be planted through slits in black polythene sheeting, pegged over the ground as a mulch, or grown in sturdy light-proof plastic bags, such as old potting compost bags. They may also be grown in large pots or planters for standing on temporarily unused areas where space is at a premium.

First early potatoes planted last month, in mild areas or under protection, may already be showing growth above ground and may be ready for earthing up to exclude light and prevent the tubers going green. If there is a threat of frosts cover the shoots with horticultural fleece to protect them. (hover over image on left)

Summer vegetables such as carrots, beetroot, chard, summer cauliflower and cabbages, kohl rabi, lettuce, radish, turnip, spring onions, peas and perpetual (perennial) spinach can now be sown in prepared beds, as weather and ground conditions permit. There is still time to sow parsnips. In colder areas, hold off sowing beetroot too early, as it may cause bolting if they become chilled. Next month is not too late for sowing beetroot, if in doubt over the weather.

Leeks can be sown outdoors on seed beds ready for transplanting to their final growing positions later. Separate seed beds can be used to sow later maturing brassicas, for planting in final positions later. Care should be taken to ensure that the ground is free of clubroot disease. If the presence of club root is suspected, then sow in modules of multipurpose compost instead. Ready-grown young brassica plants will start to be available from garden centres.

Broad beans sown in pots earlier and hardened off, can now be transplanted into their final position, without protection, and direct sowing can start if the ground has warmed sufficiently.

This month is really the last chance, this season, to plant asparagus crowns. A deep, friable, well-drained but moisture retentive soil containing plenty of organic matter is needed, and care should have been taken to remove any persistent perennial weeds.

Shallots, garlic and onion sets that have not already been planted should be planted as soon as possible, as should Jerusalem artichoke tubers.

Young pea seedlings, from March sowings, or planted from protectively raised plants will need to be supported with sticks, twigs, green plastic pea and bean netting, or chicken netting.

Thin out rows of seedlings as soon as they are large enough to be handled and remove weed seedlings. Take care when doing this to ensure that the roots of retained seedling crop plants are disturbed as little as possible. If the seedling crop plants aren’t fully established it is better to wait a week or so, to ensure they are better able to withstand some disturbance.

Plant out onions from seed sown earlier in the year under cover, in ground not used for onions for the previous three seasons. This will reduce the incidence of diseases such as white rot.

Harvesting of over-wintering crops such as leeks, winter salads, kale and sprouting broccoli can continue. Parsnips will have re-started into growth and will become progressively woody. Best to clear any remaining parsnip plants, unless growing for decorative flower heads or self-saved seed. Winter hardy spring onions, radishes, spring cauliflowers, spring cabbages and un-forced rhubarb will be ready for harvesting this month

Control germinating annual weeds by hoeing between rows during dry weather.

If not already done so, prepare your runner bean supports and trenches for sowing (under cover, in May) or planting out (in June). This will save you time later and give a slightly earlier maturing crop.

Fruit Plot

Raspberry canes, currants, gooseberry and blackberry etc. will already have started into growth early this month, or earlier in mild districts, so this is the last chance to tidy up the fruit plot for the summer. Remove any weeds and apply a mulch of well-rotted compost or manure to all fruit trees and bushes to retain moisture and deter weed growth. If not already done so, earlier in the year, a top dressing of fertiliser, particularly potash rich, will be beneficial for all fruit crops.

Blackcurrants are particularly sensitive to frosts at this time as it will cause dropping or ‘run-off’ of flowers, leading to a reduced or absent crop later. Protect by covering with fleece.

Check gooseberries for American gooseberry mildew and spray with appropriate fungicide. Keep an eye out for early appearance of gooseberry sawfly larvae (caterpillars) and spray promptly with appropriate insecticide.

This month will be the last chance to plant bare-rooted bushes, which should be completed as early as possible. Container grown

plants can be planted later, when in full leaf, but it is still preferable to plant them while dormant. Container grown bushes and trees are usually significantly more expensive than bare-rooted ones, should you need an incentive to get a move on.

Ensure that newly planted trees and bushes are kept supplied with sufficient water through the spring and summer to ensure good root growth and establishment.

Pruning of top fruit (apples and pears) should now be finished, though this can still be done in colder areas. Grafting of fruit trees can still take place early in the month. If you miss the boat on grafting you can still try ‘chip-budding’ in July.

Stone fruit will have broken into leaf this month, and formative pruning of plums, gages, damsons etc. can be carried out, both this month and during subsequent months. The reason for waiting until after leaf burst is to reduce the risk of infection with silver leaf disease as the spores are produced during wetter and colder periods. Even so it is preferable to sterilise pruning tools with methylated spirit or fungicidal solution between use. Paint a fungicidal wound solution on cut branches too.

Spraying against Apple and Pear Scab should be carried out if this is prevalent in the area. Other pests and diseases of fruit trees will start to appear as the weather improves and preventative sprays may be needed. Do not spray in windy conditions or when pollinating insects are most active, but preferably spray in late evening. Do not spray when crops are in full flower.

If you have trees grown on dwarf rootstocks it may be possible to protect flowers from frost by covering temporarily with fleece. When frost danger has passed, remove fleece promptly, to allow access by pollinating insects.

It is still possible to plant strawberry runner plants. In many cases it will be possible to get a small crop this year if the plant has established itself well. Where plants are slow to establish, pinch out the flower buds to prevent fruiting this year. Failure to get the plant established properly at the outset, will mean the plant will struggle and fail to thrive in subsequent years, thus reducing fruit yields.

Strawberries that are in flower are susceptible to late frosts, cover with fleece to protect them, but remove fleece immediately threat of frost has passed to allow pollination. Strawberry flowers affected by frost exhibit ‘black eye’, the central yellow flower disc turning black and not yielding fruit. Inadequate pollination will result in misshapen fruit. Ensure adequate water while fruit is swelling. Net strawberry plants against birds, and ensure adequate regular slug control.

Rhubarb that hasn’t been forced will come on stream for picking this month so check with spouse to keep the stocks of custard powder and sugar topped up. Forced rhubarb that has been already cropped should be rested and given a good feed to build it up again.

Pest & Diseases

Ensure that crops remaining in the ground, and new sowings under cloches, are protected from mice.

Slugs and snails always.pose a threat, but at this time of year, young tender seedlings are particularly attractive. Failure to take adequate control measures can lead to a young crop being decimated overnight. You have been warned!

Pigeons are serious pests of not only brassicas, but other young vegetables. Protection by netting, fleece, or other form of cover, may be necessary where pigeons are a problem. Rabbits may also be a problem in your area so fence off vulnerable crops with chicken wire to reduce attack.

The yellowing leaves of over wintered brassicas can harbour grey mould and brassica downy mildew, so remove, but do not compost, but put in the rubbish bin (or burn it if bonfires are allowed, and won’t cause a nuisance).

‘Damping off’ of seedlings can be a problem with sowings both outside and in modules or containers under cover. Spray with Cheshunt Compound solution to control this problem.

Insects start to emerge as temperatures increase. A mild winter may have allowed more pests to survive (such as cabbage whitefly), and an equally mild spring can see pest problems developing earlier than usual. Attracting wildlife to your plot can help to control pest problems, so set aside a small area to encourage their presence. In mild conditions birds will raise young earlier, so will require plenty of insects and other food for their developing chicks.

Flea beetle on brassicas, and pea and bean weevil can be a problem this month, and you may need to control them with an insecticide or exclude them with horticultural fleece. Flea beetle will leave holes in the leaves of affected plants (including radish and turnip), and the presence of pea and bean weevil will be apparent by semicircular notches chewed out of leaf margins. A spell of warm dryish weather will increase activity of these pests, so be on the alert, though little harm will be caused by mild infestations.

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Plot 25 - 20th April 2010 - Greenhouse raised broad beans planted in March under fleece now beginning to flower. Note protective fleece to afford protection against cold weather and late frosts. Asparagus crowns planted in narrow bed, front right. (click image to enlarge)