Head Gardeners’ tips
April 2024

Of course April can still be a chilly month, so take care not to rush those seedlings out of the greenhouse and to instead gradually harden them off in a cold frame.

April brings with it such verdant fresh green leaves that almost seem to appear overnight across hedgerows and woodlands. There is a wonderful promise of renewal and a fresh start to the growing year – our gardens are coming back to life before our eyes.

Here in Salisbury we made the most of the dormant months to rejuvenate some of our borders, lifting and dividing many of the more established clumps of perennials and replanting in smaller groupings. I am really excited to see the results of our work in the coming month as these perennials reawaken.

Some of the jobs to tackle in the coming weeks include:

• Potting up those summer flowering bulbs, including dahlias and cannas – you may have been nurturing these through the winter in dry storage. If so, now is the time to rejuvenate them, repot into fresh compost and start watering slowly. It’s always advisable to keep any new shoots covered if they are in an unheated greenhouse, as we can still get cold frosty nights this month.
• Sowing further annual flowers, vegetables and herbs – any seeds sown now tend to get a really good start quickly, as light levels rise and temperatures improve. April is the perfect month to start off zinnias which can sulk if it’s too cold as well as your cucurbits, including squash varieties and courgettes.
• Pricking out and potting on – our greenhouse is a hive of activity as we prick out seeds sown last month, including our tomatoes. Once a seedling has grown its true leaves then it can be pricked out into its own pot of a good quality peat free multi-purpose compost.
• Keeping weeds under control in the borders – as the temperatures warm and our plants start to awaken, so do the weeds. Keep on top of them regularly now, but always try not to disturb too much of the soil as this may well bring more weed seeds to the surface. It’s also not too late to mulch any bare soil with well-rotted manure to prevent further weeds germinating.
• Stakes for herbaceous perennials – building hazel or birch plant supports now over the base of newly emerging plants to provide support to new growth will help perennials such salvia nemerosa and knautia macedonica that might flop through and over other plants without support.
• Feeding our mature container plants – now is the time to start feeding your container plants as they start to regrow in the spring. We use an organic liquid seaweed feed. It is also good practice to refresh a couple of inches of compost if possible and the plant is not too congested . It may be that the soil level has shrunk in the container over the last year and would benefit from topping up. However, always remember not to cover a shrub any higher than the top of the roots, otherwise the base of the shrub may rot. If the soil has shrunk too low you may need to lift out the plant and repot with more soil beneath, in order to raise it within the pot.
• Keep on feeding the birds – if you have been feeding the birds this winter then keep this up in spring. They need our help as they busy themselves nest building!

Most importantly, make some time to enjoy that warm spring sunshine and to really observe your garden and the nature within it. I love spotting the ladybirds as they start to emerge from their hibernation, the solitary bees which are industriously pollinating our early spring flowers, and I have even spotted some butterflies already this year.