All the Gardening Tasks You Need to Tackle in May
May is when all the work you’ve put into your yard over the years begins to show. Suddenly what looked sparse and barren just five weeks ago is filled with greenery and signs of life. May is a month of hard gardening, but if you put in the time and effort now, you’ll have a summer full of flowers and fruit.
General garden care
Irrigation systems may have suffered damage during winter storms, so now is a good time to make sure the controller is working, that none of your underwater pipes have burst, and that all of your above-ground connections are intact. Go zone by zone and check each of your lines. If you are using a hose bib, get it working and then test it. It may still be raining in many parts of the country, but you’ll need an irrigation system very soon. For plants growing in full sun, you should aim for one to two inches of water per week, watering in the morning.
Your rooted beds can benefit from a layer of compost, which will act like a regular fertilizer and will also add volume to your beds if they have been eroded over the winter. Follow the compost with a layer of mulch . Taking this time to spread compost and mulch will help you evaluate each part of your garden, so take notes as you go about which areas need weeding, where there are pests, or where there are plants that look like they haven’t survived the winter.
Shrubs, trees and vines
A number of shrubs go through a flowering cycle in the spring, such as lilac and forsythia. Once they’ve finished blooming, you can prune them back, and in some cases, like lilacs, this can encourage a second bloom later in the season. Either way, it will save you one autumn task and make the garden tidier.
This is a good time to plant new woody shrubs and trees: the weather is mild and the ground should be soft after the rains. For existing trees, make sure you feed them with the right fertilizer for them this month. Your garden center can help determine which fertilizer is best for your trees. Each of these trees will begin to produce shoots this month and you should prune them as needed to maintain the shape of the tree and keep the amount of fruit the tree can bear. Make sure you only use clean pruning shears or loppers. When outdoors, carry diluted bleach or Lysol in a spray bottle.
Climbing perennial vines such as clematis, roses and honeysuckle should be emerging from dormancy at this stage and you will need to make sure you support them by tying them loosely to the trellises as they climb.
Annual flowers
At this time of year, garden centers should be full of annuals including petunias, lobelias, marigolds and begonias. Annuals are a little more tender than perennials, so you’ll need to wait until you’re past the risk of frost to plant. Annuals can fill spaces with color in the space and time between perennials’ blooms and are ideal for window boxes and flower pots where annuals may have a hard time surviving the winter. Most hanging baskets contain annuals for the same reason: they are too open for perennials or anything else to survive the winter. You can plant the baskets now, but you may have to wait until they are warm enough for them to emerge; you want to focus on nighttime and soil temperatures to determine the correct date.
Perennial flowers
Most people’s tulips are already in bloom or have just finished blooming – be sure not to cut them after blooming. Tulips need leaves to come back next year, so leave them to compost in place. Once the foliage turns yellow, the bulbs can be divided or moved. Once the tulip blooms, it’s time to fertilize the bulbs to keep them strong next year. You can also plant summer bulbs such as dahlias and cannas now if the risk of frost has passed.
If you didn’t plant new perennials in April, you can still do so now or divide your existing perennials. The soil should now be very workable and you may notice which plants are ready to be divided as you move around the garden. If you want them to bloom this summer, you should complete this task in May. When planting, make sure you use a slow-release fertilizer in the soil where you plant.
Your roses are in need of spring fertilization and at this stage they may need some shaping or help securing them to the trellis. Look for signs of stress or pests and make sure you treat them with appropriate methods. Your garden center can help.
Vegetables
In many areas across the country, vegetables will begin to go into the ground sometime in May, depending on soil temperatures, nighttime temperatures and frost risk. If necessary, start hardening vegetables such as tomatoes, peppers and eggplants.
Perennial vegetables such as asparagus and artichokes should be active now. Remember to harvest asparagus daily, only taking spears that are larger than your little finger. Once the shoots become thinner, it is time to leave the plant alone for next year. Monitor artichoke plants for ant or aphid infestations, which can be removed with a spray but will return without further treatment, such as neem oil or nearby trap flowers such as nasturtiums. Both asparagus and artichoke beds will benefit from spring fertilization.
By mid-to-late May, nearly all regions should begin planting weather-related crops. Tomatoes, eggplants and peppers, as well as beans, corn, cucumbers and everything else. Beans and corn can be direct seeded, as can melon, squash, and winter and summer squash, but using starters will give you a head start in the summer.
If you planted potatoes in the spring, it’s most likely time to hill up the soil around the sprouts.
Thin out strawberry beds of shoots . Strawberry plants can focus their energy on either producing these shoots or producing fruit, but are not very good at either task. Every spring, the beds are thinned out to obtain higher quality and larger fruits. You can give away the shoots or plant them elsewhere.
Pest Control
Reduce snail and slug populations by setting traps and regular evening hunts. Doing this now when the rains have stopped will greatly reduce problems later this summer. Hang pheromone traps on your fruit trees now to control pests this summer and protect your fruit.