There is a lot to do in the merry month of May. After 15 May, following the cold Sophie, no more night frost is to be expected. You can put out your tub plants, sow or plant plants, vegetables or herbs, tend your lawn and prepare all the trees, plants and shrubs for their vegetation phase. If the last few months have been as dry as this year, water artificially the plants that sprout in May and need more water. Also watch out for late frosts and protect anything you have freshly planted with brushwood or fleece at night. Rapid and strong temperature fluctuations can damage plant parts. Moisture must not be allowed to form under the film and air must not be allowed to accumulate. The plants need a lot of light during the growth phase.
May is crucial for a dense grass surface. The beginning of May is the last date to scarify matted or mossy lawns to improve the water and oxygen supply. After that it is too warm and too dry for this and the turf no longer closes by itself. Re-seed lawns in thin and bare patches, preferably with a fast-germinating grass variety such as German ryegrass. Enrich the soil with nutrients, for example with fertiliser or granules, which makes the lawn more resistant to weeds that take nutrients and water from the grass blades. You can also mulch the lawn, i.e. leave the grass cuttings lying around. Because the lawn grows quickly and vigorously in May, you should mow it regularly, but never cut it by more than a third or half. If you discover weeds, you should remove or destroy them immediately so that they cannot spread over a wide area.
Planting sunflowers is easy: all you have to do is plant the seeds in the soil and water them regularly. That's why sunflowers are just as suitable for the balcony or terrace as they are for the garden. You can also sow summer flowers with two growing seasons, such as bearded carnations, foxgloves or hollyhocks, directly without working the soil first. Remove all wilted blossoms from perennial flowers and plants so that they bloom longer. In the case of roses, you should cut off wild shoots at the point of budding so that they produce more and more beautiful leaves and buds. Perennials grow a lot of leaves and flowers that weigh heavily, so they need a climbing aid to take the weight off them.
In May you lay the foundation for a productive summer. Loosen the soil, this enriches the soil with oxygen and distributes the water better. Spread compost or green manure, plough under the plants and spread mulch on the soil, this improves the soil quality. Young plants in particular need a lot of care. Therefore, you should fertilise the soil every two to three weeks and water evenly without letting the moisture accumulate. Do not plant frost-sensitive varieties such as pumpkin, tomatoes or courgettes until after the Ice Saints. With tomatoes, you should also remove side shoots and repot the plants if they grow too densely. In May you can already harvest the first vegetables. For example, cauliflower, leeks or spinach. What you do not eat immediately should be stored in a dry place or frozen.
Fruit trees and shrubs need a lot of water now. The soil must be neither too dry nor too wet. Support the growth and maturation process with fruit fertiliser. Especially if you have just planted the trees or shrubs. Use bark mulch around the trunks or shrubs to prevent moisture from evaporating too quickly. Cut back the side shoots on espalier fruit and tie down the side shoots of young fruit trees. You should shorten the shoots on kiwi trees and thin out plum trees. Be careful not to overfertilise berry bushes. Too much fertiliser promotes shoot growth at the expense of fruit growth and makes the bushes more susceptible to fungal diseases or pests. You should mulch berry bushes and strawberries, fertilise raspberries, for example with a special liquid fertiliser.
Bulb flowers such as dahlias or gladioli that have spent the winter indoors or in the cellar can be put outside from mid-May, as soon as the night frost has passed. The first flowers to bloom in window boxes or planters will be geraniums, busy lilies and petunias. Now is the time to loosen the soil, fertilise the soil and cut back excess shoots. Climbing plants such as nasturtiums or showy willow grow quickly, embellish every balcony or terrace and protect against prying eyes. Rose arches, trellises or climbing frames support the growth of these annual climbing plants and form a natural privacy screen. Plant flower boxes or planters with the same summer flowers and raised beds with the same vegetables as in the garden.
You can also put houseplants on the balcony, garden patio or terrace. Start carefully and put them outside for only a few hours a day after the Ice Saints, preferably in a semi-shady place. From June, you can leave houseplants outside until the end of summer, but it is better not to place them in full sun. To compensate, you can cut the first garden flowers in May and place them in a vase indoors or outdoors. For example, peonies, which you should only cut when their buds change colour, otherwise they will fade quickly. Farm peonies last much longer in the vase than garden peonies, which wither after about 10 days.
Get the garden furniture out of its winter quarters, dust it off and set up your balcony, garden seating area or terrace. If your garden furniture is made of wood, you should treat it regularly and protect it from the weather. Varnish at least every two years, stain lasts much longer. Also think about light for outside, because the nights in May can already be warm, but the sun still sets relatively early. After the long winter break, you should now at the latest get your barbecue in shape and clean the grate thoroughly. The easiest way to do this is with a brass brush and a cleaning spray for the barbecue, which softens and removes deposits, grease and dirt. If you do not yet own a barbecue or if the old one no longer meets your requirements, you should get a new one.
As temperatures rise, so do the pests, which have a great appetite for tender leaves and young shoots. Protect carrots, cabbage or leeks with netting, check young vegetables for voracious caterpillars, put up yellow boards as protection against cherry fruit flies and plant chervil, which keeps slugs away. Additionally, protect leaves and shoots from slugs with a perimeter edging. If your currant or gooseberry bushes lose leaves or shed underdeveloped berries, you should cut back the bushes and provide them with better nutrients.