Poole in Bloom Gardening Hub -Jobs for April by David Bassil

  Sweet Peas can be sown now, directly where they are to flower. These will give you a much later crop of flowers after those which were sown earlier under glass have finished flowering.

Plant summer flowering bulbs, corms and tubers directly into the ground now for flowering this summer. 

Now is an ideal time to prune Spring flowering shrubs such as Forsythia, Abelia or Chaenomeles as they finish their display.

Feed Roses now to induce a larger crop of flowers this year. Use a balanced general fertilizer such as Vitax Q4 or a specific rose fertilizer in powder or granular form.

Continue to plant evergreen trees, shrubs and hedges.

Now is also a good time to transplant evergreen shrubs but make sure you water in well. 

A number of evergreen shrubs have suffered badly after the winter storms, particularly near the coast, by salt scorch. Now is a good time to trim back the damaged stems.

Continue to direct sow vegetables such as Beetroot, Carrots, Lettuce, Turnips, Radish and Peas.

At the end of April, Runner and French Beans can also be sown directly outside, especially if the weather is on the warm side. 

Continue to plant Potatoes and complete the planting of Onion sets, as a matter of urgency.

Cherries, Plums and other stone fruits can be pruned now, as the young shoots appear. This will avoid the problem of silver leaf disease and other fungal problems.

Look out for early Aphid attack. Prompt action helps to reduce numbers and colonies establishing.

From the end of April watch out for caterpillar-like larvae of the Gooseberry sawfly which can very quickly defoliate Gooseberries, Red currants and White currants.

 Before sowing new lawns eliminate perennial weeds. Where weeds and moss is a problem on established lawns apply a combined lawn feed weed and mosskiller.

Patches of yellow or dying grass with white or pink cotton-like fungal growth in wet conditions will indicate fusarium patch disease, also known as snow mould.

 Plant out Onion sets and Shallots now, leaving just the tip showing above soil level. 

Many kinds of vegetables can be sown now especially if you have the protection of a cold greenhouse or cloches. Peas, Lettuce, Carrots, Parsnips and Herbs are among the best for early sowing. 

Take care to protect emerging seedlings from slugs and snails as they emerge from their period of winter dormancy.  
 

This is without doubt the best time to prune your Roses, the heaviest of the frosts should now be a thing of the past and consequently dieback of the pruned shoots will be reduced to a minimum. Hybrid Tea Roses should be pruned the hardest, cutting back each shoot to around 6 inches from the base. 

Floribunda or Cluster Roses should be pruned to around 12 inches from their base. This type of pruning can only be successfully done on roses which have either been newly planted or those which have been regularly pruned correctly every year. Any that have been neglected can only be pruned back to 2 or 3 buds on the wood produced last season. Cutting back on older wood should only be done one at a time over several years as they may well not produce new growth. 

After pruning feed the Roses with a balanced general fertilizer and then mulch around the bushes with compost or manure – this will help to reduce the attack of Black Spot Disease. The spores of this fungus are now dormant on the surface of the soil and are spread to the new emerging young growth by being splashed up on to it by heavy rain. 

Climbers and Rambler Roses should be pruned by cutting away all of the older wood and tying in the new growth produced last season. Shrub Roses can be pruned into shape with a pair of shears or hedgecutters – this may sound drastic but really works well. 

Remove the dead heads from Daffodils as they fade and then feed with a high potash feed. After the flowers have finished is when the bulb needs this feeding to build up the bulb for next year’s display. The bulb is capable of this task for only 6 weeks after flowering. 

Divide summer flowering herbaceous perennials now or as soon as growth commences. When dividing large clumps such as Michaelmas Daisies, Helenium or Astilbe, etc keep only the parts nearest the edges of the clump not from the centre. 

If you have a greenhouse or some form of protection, Dahlias can be started off now by putting the tuber in the smallest pot it will comfortably go in, just covering with soil and water in. Keep only just moist and most importantly frost free. If you intend to plant directly outside, leave for another month.

Cut down the stems of Cornus or Salix which have been grown for their coloured winter stems to induce new growth from the base which will give you the best display next winter. Remove the old stems from Grasses now to allow the new growth to take its place unhindered.

Any shrub growing in a large pot should be top-dressed now with fresh compost. JI No.3 would be the best for this purpose. With a trowel remove the top 2 inches or so of old soil and replace with the new. Be careful not to damage the stem when doing this but don’t worry about the surface roots which will inevitable be cut as this will not affect the plant in any way.  

If you have not already done so, purchase now all the flower seeds you wish to grow this year. Also obtain your summer flowering bulbs and corms before supplies run out. 

Seed potatoes are best obtained now and set up for chitting (to produce their shoots) by placing in egg boxes or trays in a light frost free place. 

If you have a greenhouse and can keep it warm enough, especially at night, you can make the first sowings of vegetables such as Cabbage, Leeks and Onions in small trays and prick out into larger containers when they have germinated. 

Alternatively seed can be sown into small pots or cell trays directly. I would suggest sowing two seeds per cell and thinning out to the strongest one after germination has taken place. 

The first sowing of Tomatoes can also be made this month but the warmth is of even greater importance with this subject. 

As with flowers obtain all the seeds you need for the season 

  Autumn fruiting Raspberry canes should be pruned down to almost ground level now ready to induce the new growth to fruit for you this coming autumn.
Tidy up Strawberry plants by removing all dead or decaying leaves and any unwanted runners.
 

Prune late flowering Clematis down to about 6 inches from ground level to a pair of healthy buds.

If you have overcrowded clumps of Snowdrops, now is the right time to lift, divide and replant in the green stage. It is important to plant back at the same depth that they were in before moving. 

Fuchsias which have been overwintering in the greenhouse can be pruned and re-potted now but do not do both jobs at the same time, better to prune first and then repot two weeks later. When pruning do not be frightened to prune hard back and when repotting to move all the old compost from around the roots and repot back into a smaller pot, this will enable some room to pot on again into the final larger pot as the season progresses.

If you grow Bougainvillea and Plumbago in your conservatory, now is a good time to prune them by cutting back all growth to two buds from the main framework. This will produce many more shoots to flower later in the season. 

If you have not already done so, purchase now all the flower seeds you wish to grow this year. Also obtain your summer flowering bulbs and corms before supplies run out. 

Start to force a crown on Rhubarb now, by placing a layer of loose straw over the plant and then covering with an upturned bucket. 

Move Blueberries growing in pots to a sheltered place in the garden and wrap the pot in hessian or straw to protect the roots from any prolonged frosty spells which may occur from now on.

Grapevines can be pruned now when they are fully dormant (all leaves have gone). Pruning now or in January will prevent “bleeding”.

Check over any stored fruit and vegetables on a regular basis to check for rotting and remove urgently before the others become infected.

Brussels Sprout plants can be severely weakened by strong winds, so if yours are in an exposed site staking each plant will improve the situation no end and prevent the plants from being uprooted.

Make sure that plants growing in containers do not dry out, especially if against a wall. This is often neglected at this time of year. 

Keep gift plants such as Azaleas and bulbs cool to prolong the display. 

If you had an Amaryllis last winter and it has been rested, it can be given a first watering now to start it back into growth.

To control Brown Rot on fruit trees, cut away all mummified fruits from the trees at this time to help prevent infection next year.

Spray small fruit trees now while they are dormant with Vitax Winter Wash to lessen the number of over-wintering pests.

Keep over wintering Brassicas covered with netting to help prevent damage by pigeons. An attack will certainly occur as soon as the first cold weather arises.

Chives and Mint can be potted up now and kept on the kitchen window sill to force for winter use.

Dig up some Parsnips and Carrots and store in moist sand near to the house for winter use before the ground gets too frozen to lift them. 

Clear away all plant debris from the vegetable plot and compost, except for Brassica roots etc. 

Dig over the plot and leave rough for the winter. Incorporate manure and/or compost in early Spring.

Plant bare root trees and shrubs as soon as possible while the soil is still relatively warm. 

Remove fallen leaves which can collect among the roots of Herbaceous Perennials and cause rotting. 

Shorten the long shoots of Hybrid Tea and Cluster (Floribunda) Roses to reduce wind rock. 

Complete the planting of spring bulbs as soon as possible. 

Before the first real frosts start, protect vulnerable plants with straw or bracken and wrap around the stems with Hessian or fleece. Do not use polythene as this will cause sweating and dramatically increase the chance of losses. 

Several hardy herbaceous perennials can be successfully propagated by root cuttings taken now. Dicentra spectablis (Bleeding Heart) and Phlox are two examples.

Question 1: “Can I grow Blueberries in pots and are any varieties better than others for this purpose?” 

Blueberries do very well when grown in pots but you must have an ericaceous compost to pot them up into, also a ready supply of rainwater to water them at all times. Tap water, which is basically alkaline will severely damage or kill Blueberries if used over a prolong period An occasional watering if the water butt runs dry will do no harm, however, only use as a last resort. Among the best varieties to select from are Duke, Patriot, Spartan and Sunshine Blue. 

Question 2: “Can I fertilize and mulch my plants with manure and garden compost in the autumn or should I wait until spring?” 

Fertilizers should only be used in the spring and summer months when the plants are growing and able to take up the available nutrients produced. If applied in the autumn or early winter so much of the available nutrients will be leached out with the winter rains so by spring very little if any will still be available to your plants when it is really needed. 

Even slow to breakdown fertilizers such as Blood Fish and Bone meal or Chicken pellets are best left to late winter before applying. Mulches in the form of manure, leaf mould, garden compost are best applied in early spring because of the leaching out effect mentioned earlier. All mulches should always be applied to moist ground, never on the top of dry soil.

Make the final cut of the lawn this month but remember to keep off the lawn in frosty weather. 

Oil and grease the mower before it is stored away for the winter.

Pot plants: Reduce the amount of watering and feeding as the plants prepare themselves for winter. However, houseplants in your warmest room should be watered as often as it is necessary but feeding can now be reduced to once a month.

Check over Apples and Pears in store regularly for signs of decay before they start to rot their neighbours in the tray. 

Now is an ideal time to put Grease bands around the trunks of Apple trees to help reduce the attack of “maggots” in the fruit next year.

Check the foliage of over wintering Geraniums in the greenhouse for signs of Rust and Botrytis and remove all affected leaves urgently. 

Many other plants can be affected at this time of year with Botrytis especially if the greenhouse ventilators are not opened on every possible occasion to keep the air moving..

Plant up containers with Pansies, Violas, Polyanthus, Bellis and Wallflowers and mix with the coloured leaved forms of Ivy to trail over the edge and Spring bulbs to grow up through the display. 

Towards the end of the month we could experience the first frost, which will blacken the growth of Cannas, Dahlias and other tender perennials. 

When this occurs, cut off the growth at just above soil level and dig up the roots with some soil still attached and store away for the winter in a dry and frost free place in an upside down position. This will drain moisture away from the crown as the stems decay and the drying out process continues. Do not be tempted to cover the roots at this stage and certainly never cover the roots with polythene at any time. Alternatively, some people prefer to leave the roots in the soil particularly if you have a well-drained soil. If this is so, cover over the crowns of the plants with a mulch of straw, bracken, leave mould or old potting compost to a depth of 10cm (4”). The plants should then come through the winter unscathed. 

 Plant new trees and shrubs now while the soil temperatures are still relatively warm, this will greatly aid their establishment. 

Propagate ornamentals such as Roses, Cornus, Forsythia and Philadelphus by hardwood cuttings. Cut a piece of this year’s growth and trim to approximately 9 to 12 inches in length. 

Remove the top section and cut just below the leaf bud at the base of the cutting. Insert about two-thirds its depth in the soil where it can be left undisturbed for the next twelve months or insert several cuttings around the edge of a deep pot and leave outside in a sheltered position.

  Pick the last of the apples as they ripen and plant any new fruit bushes required now. 

Prune out the old fruited canes of Blackberries and other hybrid berries and tie in new growth to supports.

Apply grease bands around trunks of fruit trees to protect from winter moth damage in spring.

Finish the planting of Onion sets and Garlic. 

Continue to harvest Pumpkins, Squashes and Marrows. 

Lift the last of the Potatoes before frosts start.

  Rake up fallen leaves around Roses to limit the spread of Black Spot and other fungal diseases next year.