Brian answers readers’ horticultural queries
Q: How do I use eggshell to stop slugs? PD, Cosham.
A: After using the oven for a roast, put the eggshells in for 10 minutes. Crush them with a rolling pin. Scatter the crushed shells over the soil’s surface and the slugs will keep off.
Q: We have a beautiful forsythia in full bloom in our garden. It is almost 12ft tall and I want to prune it really hard. When is the best time to do it please? HD, Cowplain.
A: Use a pruning saw and cut it back hard as soon as it stops flowering. Retain the strong straight branches growing up from the base, but nip out the tips for wonderful flowers next spring.
Q: I have grown an apple tree from a pip sown about six years ago but my family tell me I am wasting my time as it will take years to fruit. I have not told them, but I had just one apple which ripened last October and it tasted wonderful. Will pruning induce more fruit and how do I do it? ND, Eastney.
A: I thought your letter was a delight. I have sent you a diagram showing how to prune the apple based on the photo you sent me.
Q: I have built a cold frame and treated the wood with creosote substitute. I have not put the glass on top but when will it will be safe to plant lettuce in it. AP, Emsworth.
A: If you are going to plant lettuce plants, wait for two weeks. If sowing seeds directly into the frame’s soil, do it a week after treating the timber. Leaving the glass off allows the fumes to escape. Creosote substitute is a good wood preservative.
JOBS FOR THE COMING WEEK
This is the best time to buy those lovely surfinia petunias, scaevola, ivy-leafed geraniums and other gems we all enjoy growing in baskets and tubs. These can all be propagated by keeping them warm in a plant propagator. (Did you treat yourself to a soil-warming cable? It isn’t too late). Pinch out the tips of the plants and they will produce several side shoots. Cuttings a few inches long can be taken to increase the number of plants you need.
If you have space, tomato plants may be planted in the greenhouse in growing bags. You need a heater to protect them from frosts. Only three in a bag. A bottomless 10in-diameter pot placed over the top of the hole made in the growing bag for the plant and filled with compost is a good idea because it makes correct watering a lot easier.
Have some horticultural fleece handy just in case we have a nasty frost because severe frosts will penetrate the glass if there is no heat in the glasshouse.
Sow seeds in the greenhouse of the rapid-growing plants such as French marigolds and zinnias.
Take hardier bedding plants such as antirrhinums, alyssum and asters out into a cold frame but cover the top with carpet if frosts are likely.
Trim the hedge as soon as new growth starts and plan to cut hedges every six weeks. It takes far less time to cut hedges if this nasty job is done regularly. Don’t do this if the birds have built a nest. If they have, wait another four weeks.
Sow seeds outdoors of beetroot and mid-season Brussels sprouts and late cauliflower.
Earth-up early potatoes using well-rotted compost and water the plants regularly to avoid potato scab. Moist soil helps prevent potato scab.
Watch out for greenfly on roses and blackfly on broad beans. Use aphid control liquid in the late evening to control these pests.
Don’t clean up all the little bits around the garden, the birds will pick them up for nesting materials.