April: New Growth (and new weeds!)

• Protect tender new growth from frosts by covering with newspaper or horticultural fleece at night if possible.

• Keep the greenhouse well ventilated and water regularly as warm days and rapidly growing plants will dry soil quickly.  

• In the vegetable garden, it’s time to direct-sow carrots, parsnips, radishes and beets.

• Chitted seed potatoes should be planted now, especially first-early potatoes that will be ready to harvest in about 12 weeks. 

• Continue to mow lawns regularly with blades set higher than normal.  Moss and broadleaf weeds should be treated now.  

• Fill in any depressions in the grass and over-sow any bare patches with new seed. 

• Finish dividing any herbaceous perennials or use the new shoots that are emerging as material for propagation either by division or as cuttings.  

• Leave the foliage of Spring bulbs to die down naturally – don’t be tempted to cut or tie.  It’s a good idea to give them a water with a high potassium fertiliser such as a liquid tomato feed.  

• Start the biological control of Vine Weevil larvae with the application of a nematode soil drench, and Box Tree Moth caterpillars with a bacterial wash (for example, Dipel or XenTari). 

• Pot-up houseplants into a slightly larger pot.  Alternatively, remove some of the compost and roots at the bottom of the current pot and refresh.  If plants are in flower or just about to flower, wait until the flowers fade before repotting.

• Continue to sow annuals and vegetable seeds, and prick out and pot on any seedlings as they grow.  Hardy annuals can be sown outside where they are to flower, or you can sow in trays undercover or in a sheltered spot.