Trees, Shrubs and Roses
Continue to prune spring shrubs as they go out of flower, if are growing too big and don’t delay any further with forsythia, flowering currant, kerria and spring spirea. Tie in the new shoots of climbing roses so that they will be in the correct position for training later. Continue to spray roses against blackspot disease, especially in the damper parts of the country and after wet weather. Water recently planted trees and shrubs in dry spells to encourage rooting out in to the surrounding soil.
Bedding plants should be planted out in the coming two weeks or so. Prepare for planting bedding by digging the ground, removing spring bedding if necessary and digging in some well-rotted compost.. Bedding tulips and other bulbs can be lifted and moved to a place where they will be allowed to flower again in future years. Dahlias and corms of gladiolus can be planted out where they are to flower. Slugs and snails are active in warm wet weather and they can cause severe damage, especially to susceptible plants like hostas and rodgersias. Stake perennial flowers that need it, if you have time.
Grass growth is generally good during May and June and the lawn is unlikely to need feeding for a while but any lawn that is pale or growing poorly should now get some lawn fertilizer, a high-nitrogen fertilizer.Carry out lawn repairs, or over-sowing patchy lawn with grass seed, soon before the soil dries out again and the opportunity is lost. Re-cut the edges around flower beds or borders, using a half-moon edger which the soil is firm but moist enough to cut into the sod easily.
Fruit, Vegetables and Herbs
Sow cabbage and cauliflower for autumn and winter use in the coming weeks. In mild areas, plant out tender vegetables such as sweet corn and runner beans. Wait a week or two in colder areas, or if the weather is cold and windy, grow on these plants, feeding them in pots if they are hungry and reducing the temperature in the greenhouse by ventilating, to slow their growth. Spray apple and pear trees for scab disease and check for greenflies at the same time. Make a sowing of maincrop carrots. Repeat sowings of vegetables sown early, such as lettuce and peas, can be made now. Thin out vegetables that have reached suitable size.
Greenhouse and House Plants
Plant out tomatoes, chilli peppers, cucumbers and sweet peppers if there has been no space earlier in the greenhouse due to bedding plants and outdoor vegetables such as sweet corn and runer beans.If you have not raised plants of your own, all of these are available in garden outlets. Feed greenhouse plants strongly now to get good growth as early as possible and water well. Watch for pest build-up on greenhouse plants. Spray a grapevine with rose spray if it had mildew disease last year. Remove excess shoots of a grapevine every couple of weeks to keep it under control and tie in new shoots that are needed for extension growth. Houseplants can be re-potted now. Reduce watering for tomato plants as they set their first truss of fruit.If a lot of peach fruits have set, thin them out to an average of 1 fruit per 20cm of branch, leaving the larrgest ones.