For a while now, the RHS has been running a campaign promoting the benefit of gardening for mental health and wellbeing for individuals and communities and the prolonged lock-down is bringing home to those of us lucky enough to have a garden what a huge benefit they are. We are not confined to four walls, there is always something to do and we can enjoy all the benefits of being in the open air, hearing the birds sing and revelling in a long period of wonderful sunshine. Lovely as it has been to see the April sun, gardeners will have been thinking it was time for rain and today, as I write this, there has been some really good rainfall; perfect timing to save me putting the sprinkler on the lawn after a treatment of fertiliser …Extra time available for gardening means that this could be the year of doing things when they should be done rather than feeling that we are always trying to catch up. It’s always worth spending a while just looking round and seeing what needs to be done. Apart from growing things that also means getting sheds and greenhouses clean and tidy and getting tools into good shape with tools clean and secateurs, shears and loppers kept sharp. With regard to sharpening I have used a few special gadgets but, last year, I bought a sharpening stone that you wet during use and this has been better than anything else.
May is the month for planting out annual bedding but this may be difficult this year with garden centres and nurseries closed. If you grow your own from seed you will be well away. They can be hardened off now by putting them outside in their seed trays or pots on warmer days or opening a cold frame but don’t plant them out until the second half of the month in case of a late frost. You may have been able to order plug plants on-line from the major seed companies like Suttons or Thompson and Morgan and you may be able to find a garden centre or nursery offering a delivery service. I understand Cottage Garden Plants at Cardington is making deliveries and it will be worth trying other local nurseries at Kempston or Box End. If you have overwintered dahlias, geranium and fuschias indoors they should be growing now and can be planted out also from the second half of May. They can be left in pots or planted in the open ground. Plants kept in last year’s soil will do better if repotted in fresh compost (John Innes no. 3 is good). Plant with bonemeal or other general fertiliser and
Dahlias should be planted together with a strong stake put in first to avoid damaging the tuber. Dahlia plants in growth should be restricted to a maximum of three shoots. Spare shoots cut off can be used for cuttings.
You may have already sown tender vegetables, such as courgettes, cucumbers, sweetcorn, french beans and runner beans, under glass but it is not too late to do so. It is best to sow them in small individual pots or start them off in a seed tray and prick out into individual pots. Courgettes, cucumber and sweet corn need to be started off with some heat, either in a propagator or in an airing cupboard or other warm place. Remove from heat immediately after germination. Brassicas sown under glass will soon be ready for planting outside. If possible, provide protection with netting or with black cotton strung across them; I tie the cotton to small sticks from apple and pear tree prunings. You have, hopefully, already made sowings of root vegetables but you can prolong harvest by later successional sowing, especially with carrot and beetroot. Beetroot thinnings make good salad leaves. Lettuce needs to be sown every couple of weeks in small quantities. They can be sown in open ground but I generally start them off in a pot or small seed tray for planting out later. This helps to reduce losses from slugs and snails.
Plants will grow strongly in May if they are fed and watered. Roses need plenty of water but only two feeds a year; in spring and late summer. Clematis amply repay fortnightly high potash feeds such as seaweed or tomato fertiliser. Tomatoes under glass need feed applied weekly once the first truss has set fruit and every three or four days after the second truss. Outdoor tomatoes should be fed every ten days or so and potatoes fed every couple of weeks with tomato feed, seaweed fertiliser or occasionally with chicken manure pellets. Potatoes should be earthed up as the plants grow as a good depth of soil will stop potatoes becoming green.