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April is a busy month in the garden! The ground is ready for planting and many trees, shrubs and perennials are showing the signs of spring. New green growth and spring blossoms are everywhere you look. Now is the time to take action in the garden! Fertilize and prune your deciduous trees and shrubs. Plant spring vegetables and annuals, along with any spring-flowering trees and shrubs you may want to add this year. Keep an eye out for encroaching weeds and spring pests and welcome back our pollinating friends: bees, butterflies and hummingbirds! April is full of activity!
Time for Spring Planting!
Now is the time to plant spring-flowering trees and shrubs and to get most annual seeds and starts in the ground. Members of the mustard family (Brassicaceae), such as broccoli and kale, can be planted now, either from starts or seed. Leafy greens, like spinach and lettuce, may be planted as well but don’t plant the warm weather-loving squashes (Cucurbita sp.) or tomatoes (Solanum sp.) for another month or so. If you are starting them from seed inside, early April is the time to do it, for transplanting in late May or early June. For tips on planting annuals, please visit the May section of our Gardening Calendar.
Come down to the nursery to see our fabulous spring display! Choose from dozens of varieties of annuals and vegetables for your gardens. Many spring flowering plants, like petunias, can be planted in April. Consider adding more trees and shrubs to your landscape as well! Japanese maples and rhododendrons can go into the garden in April to add lovely color to your garden this season. For tips on how to plant trees and shrubs, please visit the September section of our Gardening Calendar.
Pruning Deciduous Trees and Shrubs
Spring pruning promotes healthy growth, eliminates dead wood and extends blooming for many plants. This revitalizes and stimulates new growth! A healthier plant is a lovelier plant, with more blossoms, a good-looking shape and lots of natural beauty. Properly pruned fruit trees will produce more fruit. Many trees and shrubs require regular pruning in order to thrive.
Proper tools are needed for the job, depending on the size and type of plant you are pruning. Hedge clippers, pruning shears and loppers are all handy to have for various pruning jobs. For big jobs, like cutting thick tree limbs, a handsaw may be helpful but for many pruning tasks in the garden, the smaller tools do nicely.
When pruning trees and shrubs, start by eliminating dead wood: any dry limbs, without leaves, that breaks easily. It is important to remove any damaged wood, either by weather, accident or disease. Otherwise, the plant will put all of its energy into trying to heal the injured portion, rather than focusing on its overall health and new growth. Prune any branches that are growing into pathways or crowding other plants.
There are several pruning techniques that can be handy to use.
Thinning: remove branches where they join at the stem, cutting just above the branch collar (the raised area at the base of a branch). Thinning should be used to cut back dead and damaged wood, and to help a plant regain a healthy shape.
Heading: cutting a branch back to where a bud has formed or to the tip of a side branch. This technique should be used to stimulate new branch growth in a plant.
Renewal pruning: cutting the plant back to just a few inches above the soil: a great technique to stimulate fresh growth in shrubs and cut back the thick, woody stems. This works well for Hydrangea and Lilac.
Regular pruning adds vitality to many plants, trees and shrubs, as well as making them more attractive and colorful.
Beware the Cabbage Root Fly
We gardeners are on guard against all types of pests who would like to attack our precious plants. From slugs to deer, we have our methods for dealing with them. However, the cabbage root fly (Delia radicum) seems to elude many vegetable gardeners, wreaking havoc on the spring veggies and causing mass disappointment. The cabbage root fly is a tiny insect that you may see hovering around the base of cabbage family plants (broccoli, cauliflower, etc) or many root crops (beets, carrots, etc). The fly lays its eggs at the base of these plants. In six days, the maggots hatch and begin to eat the roots and stem of the plants, until the plant wilts, falls over and dies. Then, they form pupae and hibernate in the soil until next year, when they return to repeat the process.
You can spot cabbage root maggot damage by a sudden yellowing and drooping of foliage. If you dig down an inch or so around the base of the plant, you will see the big holes chewed in it. If you see the damage, it is too late to save your plants. Instead, pull and dispose of the infected plants but do not put them in the compost! Refrain from planting any susceptible plants in that same area the following year and dig out and discard any pupa you find (rusty red oblong shapes).
The best thing to do it to prevent the attacks before they start! If you spot the tiny flies hovering around your plants, take action immediately! Spraying them with an organic pesticide may have some affect but what we really want to do is prevent them from laying eggs in the soil. Laying down a weed control fabric can be very effective in prevention. Secure the fabric on top of the soil, cutting small holes in it, where your plants will fit through. Make sure there is no room for the tiny flies to get into the soil at the base of plants. You can also cut large circles of it, to fit around the base of plants (see photo).
The biggest prevention method is to lay down floating row cover over your susceptible plants early in the season, and bury it into the soil around the edges. Row cover keeps plants warm and will protect them from the flies and other pests (both slugs AND deer)! For more information on row cover, please visit the November section of our Gardening Calendar (link).
Herbs are a charming and helpful addition to the garden, both for their culinary uses and their fragrant, attractive presence. Many herbs, like sage (Salvia sp.), are perennial and, if tended and harvested, will continue to thrive in the garden for years. Herbs can either be grown from seed or transplanted from starts. Many herbs can be taken from cuttings or portions of the roots and transplanted into fresh soil.
Try growing a few herbs in containers! This has several advantages: they can be placed near the kitchen or the back door, for easy harvest around dinner time and you can save garden space! Another benefit to containers is that you can, as the name suggests, contain them. Many herbs, such as mint (Metha sp.) and lemon balm (Melissa officinalis), will spread rapidly in the garden and, if they are not restricted, can easily take over a space. These vigorous perennials spread through their roots and, in a short amount of time, take over entire beds. Growing the herbs in containers is an easy fix to that problem!
Most herbs are very low maintenance, with minimal watering requirements and a high tolerance for poor soils. They will grow in dry, sandy soils and even in gravelly places. However, drainage remains an important factor for most herb root systems so heavy clay soil should be amended in order for herbs to really take off.
Many herbs, because of their strong smells and high percentage of volatile oils, repel insects and animals who might try to harm them or other plants in the garden. They serve as garden protectors! They also serve as a pollinator attraction- bees and butterflies love tiny herb flowers and will keep coming back to your garden for more! With their beauty and scent adding to the atmosphere, their culinary prowess and roles in the garden ecology, it’s easy to see why growing an herb garden is a most excellent suggestion.