The Garden in May - Jobs and Tips
plants for May
Jobs / Tips
As the flowers of spring flowering shrubs fade, they can be pruned back to get a good display next year. Forsythia, Ribes (flowering currants), Kerria japonica, Chaenomeles (Japanese quince) and early flowering Spirea should all be pruned after flowering to keep them vigorous and flowering well. Ideally each year you should cut out one in three or one in four of the oldest braches down to ground level. In this way, the plant always has plenty of growth left and no branch is allowed to get old and past its prime.
If you have a neglected specimen of one of these plants, then they can withstand being cut pretty much right down to the ground, though I prefer to carry out drastic renovation over at least two years. Leaving some of the more upright and further back shoots intact so as to keep the plant going rather than dependent on reserves in the roots when recovering. If you do cut it right down, then expect at least one and maybe two years before it flowers again.
Lower the lawn mower height to the normal setting now. Initial mowings in early spring should be slightly higher than normal, after a couple the blades can be lowered. Remember that little and often is the best way to get a really good lawn. If you don't take much off each time, then it takes less time to do overall.
Give your lawns a feed of fertiliser now, buy a proprietary lawn feed and follow the instructions carefully. A commonly reported lawn "ailment" is caused by people who over-feed their lawns and then wonder how to deal with the dead patches. Adding some other chemical won't help, watering to dilute the feed and the passage of time will.
Weed, weed and thrice weed. They're coming up thick and vigorously now, so start while they're relatively small and you'll stop them from seeding and have a chance of staying on top of the situation.
Continue to protect young shoots from slugs. Slug control
Push support stakes into the ground around emerging tall perennials. This will enable them to be supported from the earliest opportunity and cause the least disturbance to them when they are covered in leaves. It also helps to disguise the supports later on as the plants grow around them.
Plant up containers and hanging baskets with tender summer bedding plants towards the end of the month, but don't put them out until all risk of frost has passed. If you can't keep them frost free, then order them in advance. If you do have the space in a greenhouse, then such containers and baskets are best planted up a few weeks before they are due to go out as this allows the plants to grow into their new homes and around each other.
Trim quick growing hedges. They're starting to sprout well now and it helps keep them in shape before they get too unruly. Most hedge types can be left until early to mid summer, but the faster growing varieties need 3 trims a year.
Watch out for early signs of aphids. Mild winters mean that more survive than in a cold one. It's about now that they start to come out of hiding and build up their numbers. If you can spot aphids early, then life gets an awful lot easier later on in the year. Check the newly emerging shoots of their favourite plants, particularly roses. My stage-one aphid eradication involves simply rubbing them between my fingers, you'll never get them all this way, (it's not too distasteful when there's only a few - wipe your fingers on the grass) but it's a good way of setting them back a couple of weeks or more. Stage-two involves chemicals. anti aphid
Spring flowering bulb care - The daffodils have all been over for some time, as have the hyacinths, but there's still plenty of tulips in full bloom. They don't need any cutting off, tying up, bending over or such like. Remove the faded flowers so that they don't start putting their energy into making seeds and give them a good feed of double strength liquid plant food, especially if they're growing in grass. Just the one feed will do, no need to repeat it, give them a good soaking so that the water gets well down to the roots. As a rule of thumb, you should leave the top-growth after dead-heading for at least 6 weeks after flowering before removing the foliage, longer if possible and ideally just leave them to die down and turn brown in their own time before removing them, this is the time that they have to build up the energy for next years flowers.
Any bulbs that were in containers in the house, they can be left in the pots and put outside in a sunny position, water and feed them like any other container plant until the leaves die down and then keep the bulbs in a dark, dry place until the autumn when they can go in the soil. Don't try using them in the same way again as you'll be disappointed, they will probably have been prevented from flowering last year in order to build the bulb size up to give the best performance after you bought them. In fact next year will be a bit disappointing even if you put them in the soil, but their second year in the soil and afterwards will be worthwhile. Before long, they'll be filling the garden. Pretty good value I reckon from something that cost the same as a bunch of flowers - years and years extra for free.
A "must buy" if you haven't already got any yet are pots of sweet pea seedlings. They have the advantage over many similar plants in that they're hardy and so don't need to be kept in a greenhouse or take up huge amounts of windowsill space. They benefit from protection though, so keep them under shelter if you have any, or in a sheltered part of the garden if you don't until the days start to get warmer.
Put about 10-12 plants into a large container, say 18" square or diameter, arrange a wigwam of 4 x 5ft or so high canes with string across them to bridge the gaps and interplant at the bottom with 4 viola plants. Before long, the sweet peas will be up the canes hiding the wigwam and as long as you remember to dead-head, will provide you with weeks of glorious fragrant flowers.
Summer bedding is particularly useful if you've a new garden maybe with some gaps between the shrubs and perennials because they haven't yet grown large enough. Choose larger plant varieties and group them in 3's and 4's, as they're usually frost tender, they'll have gone by the time the permanent residents have grown up.
Don't plant out any frost tender plants until at least the middle of May and preferably towards the end.
If you do have any outside and it looks like a frost maybe due, then bring them in if possible to a greenhouse, cold frame or even a garage or shed over-night.
Don't cast any clouts before the end of the month. There's an old English phrase "N'ere cast a clout 'ere May is out". Which is well known but the meaning a bit obscure. It originates in Lancashire where "clout" means clothing (as well as a smack) and the "May" is not the month of May, but the Hawthorn which flowers in May along the hedgerows and so is often called May itself. So it means don't cast off any clothing until the hawthorn blossoms (not until the end of May) - or make sure you still keep your winter underwear on until later than you'd think.