April in Your Garden

Top essential jobs 

1. Keeping both perennial and newly shooting annual weeds under control is a top job this month.

2. If you grow top fruit such as blackberries and currents, they will be setting now but protect plants from late frosts to ensure the young fruits don’t drop.

3. Tie in climbing roses if you have not already!

4. Continue sowing hardy annuals for summer flowers.

5. Sow repeat vegetable crops of radish, carrots, beetroot, and lettuce. 

6. Health check your house plants by taking outside to water and wash foliage on warm days.

7. Feed shrub roses - blood fish and bone are traditional, but seaweed is also very good.

8. Sow seed in bald patches of the lawn.

9. Prune fig trees. 

10. Divide water lilies in ponds and other water bodies now.

 

 

Sowing and planting

• Hardy annuals can be sown into pots, or modules to provide colour in the garden. Annual grasses can be fun to try too: Briza maxima, Lagurus ovatus and Hordeum jubatum are great easy to grow examples. In mild areas with light soil you can sow directly outside by marking out irregularly shaped seedbeds and broadcasting ‘drifts’ of different seeds to give a more natural look, try calendula, love-in-the-mist and other easy flowers this way.
   

• Modular trays are useful for sowing half-hardy summer plants such as marigolds (Tagetes), Lobelia, and Petunia, be sure to label each seed tray. You will need to sow them under cover, or in a heated propagator, then put them outside when the weather is reliably warm day and night.
   

• Sweet peas can be sown outside this month. Plant out autumn-sown sweet peas that have been raised in pots and prepare your wigwam supports for them to climb using a light twine to tie the plants in.
   

• If you started sowing early in March, or even February, you may have modules of young hardy annuals now ready for planting out.
   

• Plant summer-flowering bulbs, if not done already. Prepare the soil first to ensure that drainage is sufficient and prevent the bulbs rotting. Anemone coronaria tubers, for instance, need particularly well-drained soils.
   

• You can still plant herbaceous perennials such as Geranium, Astrantia, oriental poppies and more exotic plants such as Agapanthus and Calocasia. Check that the plants you buy have strong, green shoots and plant them into well-prepared soil, there are several good online mail order businesses to choose plants from.

 

Cutting back, pruning and dividing

• It’s warm enough to prune Penstemons and other slightly tender plants such as Teucrium and lavender. Make the cuts just above fresh, new shoots.
   

• When pruning perennials some plants benefit from having their flowering shoots thinned out. Although this results in fewer blooms, they are larger and of better quality. Delphiniums, lupins and phlox all benefit from this process.
   

• Divide herbaceous perennials when they are too large for their allotted space, are flowering poorly or have lost their shape. Bamboos and clumps of bulbs, or rhizomes can be divided in the same way. When transplanting the divisions make sure they have roots, shoots, and are given adequate water to settle into their new positions. In my videos on the website you can watch me easily dividing perennials if you are unsure how to deal with mature plants.

 

General work

• Put supports in place for perennials before they get too large. Criss-crossing strings from hidden, or decorative posts work well, allowing stems to grow up into the gaps between strings.
   

• Top dress spring-flowering alpines with grit, or gravel to show off the plants and to help prevent stem rots.
   

• Remove faded daffodil and tulip flowers, nipping off the heads and seed pod at the same time.
   

• Deadhead pansies, primulas and other spring bedding plants. Pansies will carry on into the spring and even to early summer if attended to frequently.
   

• It is now time to remove tired bedding and plants that did not survive the winter, these can be composted. Early removal not only keeps the border tidy, but reduces risk of pests and disease.
   

• Check that self-seeded forget-me-nots aren’t smothering other border plants. Pull out plants if necessary.
   

• Hoe borders to prevent annual and perennial weeds from spreading and seeding themselves.
   

• Herbaceous perennials infested with couch grass and other perennial weeds should be lifted so the roots of the weeds can be removed.
   

• Any mulches may need replacing after weed removal.