There’s plenty to do in the garden in March, particularly with all the warm weather we’ve been having. Spring officially arrives on March 20, and here in Southern Ohio, the last frost date is April 13. It’s time to finish up our winter chores and get started on early spring fun!
- Remove all the leaves, fallen twigs and branches. Even if you did this in the fall, more have probably blown your way or fallen.
- Cut off the ratty-looking foliage of perennials that are above ground.
- Dig out all the weeds you can see.
- Cut back vines that are growing where you don’t want them.
- Cut back ornamental grasses, including liriope, and the dead stems of perennials if you left them up for the winter (which is a good idea, for wildlife) to a few inches high.
- Use a cultivator or gloved hand to loosen the mulch, acorns and other dried plant matter covering the ground around your shrubs and perennials. This allows water and air to more easily penetrate to the roots.
Why do all that now, so early? Because if you have spring-blooming bulbs or perennials that emerge early in your borders, they could be trampled on if this clean-up is done after they’ve emerged. Or worse, if you wait til your garden has started producing masses of new growth, you won’t be able to see those weeds and out-of-control vines. Weeding now will reduce your weeding burden throughout the entire season.
Applying organic compost on top of your garden is the single most important thing you can do for your garden every year, bar none. That’s because it prevents weeds, regulates soil temperature, and retains moisture. Plus, as it decomposes over the course of the season and is carried underground by earthworms and other creatures of the soil, it improves soil structure, which means better drainage and better use of nutrients. In my garden organic compost is the only form of fertilizer I use. Like weeding and leaf removal, composting is a job that’s easier to do before new bulbs and perennials have emerged, especially if they’ve just popped up and are hard to see.
Late March/early April is a great time to prune trees and shrubs that have dropped their leaves because you can see what you’re doing. Also, because they’re dormant, they won’t respond by sprouting new growth that could be killed by cold spells.
- Remove broken branches. Bleeding sap doesn’t hurt them, so don’t worry about it.
- Remove bagworm bags now. Destroy them or throw them away; don’t just leave them on the ground.
March is a good time to prune hydrangeas, butterfly bushes, spireas, caryopteris, forsythias and crape myrtles — if needed or desired.
Installing New Plants, Moving Old Ones
Buy and plant shrubs and perennials as soon as they’re available in the stores — the sooner the better. It gives them more time to get their roots established before the heat which is much more of a killer than winter cold. Be careful not to disturb still-dormant perennials, though, so if you’re not sure where things are, wait.
And if, like me, you like to rearrange/redesign practically constantly, early spring is a great time to do that. The more time they have to get settled into their new location before it gets hot, the better. (It may be counter-intuitive, but it’s heat that’s usually responsible for killing new plants, not cold.)
Top 10 jobs this month
- Plant shallots, onion sets and early potatoes
- Protect new spring shoots from slugs
- Plant summer-flowering bulbs
- Lift and divide overgrown clumps of perennials
- Top dress containers with fresh compost
- Mow the lawn on dry days (if needed)
- Cut back Cornus (dogwood) and Salix (willow) grown for colourful winter stems
- Weeds come back in to growth – deal with them before they get out of hand
- Start feeding fish and using the pond fountain; remove pond heaters
- Open the greenhouse or conservatory doors and vents on warm days
Sow half hardy annuals
If it is fairly warm sow half hardy annuals now. If it is still cold wait until next month. Begonia, verbena and salvia are all good choices.
Now is the time to plant summer-flowering bulbs. Bulbs, corms and tubers such as anemone and gladioli all add striking colour and are also useful in the cutting garden. Scented lillies should be dotted around the garden so that you can smell their delicious scent throughout the garden.
These should be divided ‘in the green’, divide straight after flowering.
Finish pruning roses.
Make sure there are no weeds or plants immediately around the base of the rose plant.
Plant bare – rooted roses
Add a fertiliser rich in nitrogen and potassium to your roses. Hoe into the soil at the base. Think of your peonies at the same time.
Now is the time to trim lavender bushes before spring growth gets under way. Curry plants (Helichrysum italicum) can be treated the same. Trim into a ball but be careful not to trim down to the old wood at the base as new growth will not form from here.
If you have not already now is the time to prune late-flowering (group 3) clematis. Prune each stem back close to the ground.
Now is a good time to divide perennials.
To divide, dig up the whole clump, and divide into smaller pieces. Either tease the clump apart or cut using a spade. Replant in groups of three or five for good displays the following year.
In the Potager
Buy seed potatoes, place upright in an old egg box and leave, in a cool, bright position, to sprout.
If the ground is not cold and wet plant onions and shallots.
Think of sowing a row or two of flowers into your vegetable garden. These not only make the garden look more attractive and provide flowers for the house but they camouflage your vegetables from predator insects insects to the potager. Cosmos, sunflowers, sweet peas are all useful. The smell of the flowers can also stop non beneficial insects from spotting your veg. French marigolds (Tagetes) are good at deterring cabbage butterflies from cabages and produce a root secretion that destroys root-eating nematodes.
Cover the ground around strawberry plants with a good mulch of clean dry straw.
Sow peas. Rake the earth to a fine tilth and plant the peas at a depth of about 3cm, 5cm apart. Water copiously. Growth starts even quicker if you soak the peas overnight before planting.