September 13, 2016
The september checklist
What can we do in the garden in September? It’s tricky because technically this month is our first step into autumn, but in reality it often still feels like the middle of summer with temperatures capable of soaring into high digits.
I use September to re-organize, re-landscape, divide and conquer perennials and move shrubs and small trees around.
The ground is warm – perfect for settling in new plants or moving divided ones. The air (on a balmy September day) is not too hot, not too cool, just right for allowing transplants to settle in to their new location.
September is also the perfect month to start installing changes you’ve been thinking about all summer. Reworking a perennial border. Putting in a new lawn. Replacing a flowerbed with paving. Or perhaps putting up a new arbour or arch.
Think of September as our “second spring” and you’re on the right track; it’s a great time to plant and re-arrange and upgrade and refine to achieve an improved, enhanced, better-organized garden for next year.
Now let me name some of the projects that can be done this month, although I would understand if you decided instead to do nothing but sit on your patio and sip prosecco.
If you have a pond located under deciduous trees, this is a good time to put up a net to catch falling leaves. It will save you a mountain of messy work later on.
Move shrubs and perennials into a better place. Remember to prepare the new site first. This will mean plants lifted from the ground don’t have to sit and risk roots drying out while you dig.
Small shrubs, rhodos, azaleas and baby trees (especially ones you put in the wrong place in spring) can be moved quite easily. Bigger plants will need more preparation for a move and more careful digging.
Divide large clumps of perennials. You’ll know some of them need it if they look like a doughnut with nothing in the middle. Simply slice clumps into smaller portions – and plant divisions immediately.
Do a little judicious pruning. Clip late-summer flowering shrubs, such as rock rose, and cut back climbing and rambling roses.
Get set for spring
September used to be a wet month, but over the past few decades it has been warm and dry – more an extension of summer – which means shrubs like camellias, rhododendrons, magnolias and lilacs benefit from being watered to protect buds set for spring.
Start buying spring-flowering bulbs and planting from Sept. 24 on. Make sure you have a working quick-release bulb-planter and a dibber. It makes the job so much easier. Nice to have all these things all set up in the wings, ready to go, by the end of the month.
Grow some grass
If you have been thinking about upgrading an existing but weak and scrappy lawn, this is the month to do it. Seed with a quality perennial rye, which should germinate quickly. Sod will also root very quickly.
Lawn care involves mostly doing again what you did in spring: over-seed, lime with a good slow-release granular lime, feed with a slow-release, root-boosting 1-2-3 ratio fertilizer.
Ornamental grasses are at their best right now, so it’s a great time to shop for them as you can see exactly what you are getting. In spring, warm-season grasses such as pennisetum and miscanthus look miserable in their pots. Only gardeners who know how they can change buy them. If you’re planning a border of ornamental grasses, this is the time to figure out which ones to plant.
Harvest your summer-planted, cooler-season crops of lettuce, cabbages and cauliflowers, scallions and bok choi. You should still be getting good crops of late-season tomatoes and peppers plus a bountiful grape harvest.
Plant garlic later this month. Italian friends tell me the hardneck purple Russian Red variety is the best and most flavourful.
Plant a tree. I noticed fantastic deals on trees this year at unexpected places like Canadian Tire and Superstore where lovely maples and cherry trees were selling for $50. I’ve already planted a little woodland or I would be doing this in a minute.
Fall for flowers
If you feel your garden needs more colour, add some fall chrysanthemums or rudbeckia, helenium, echinacea, asters or sedums.
To keep your hydrangeas as blue as the sky, sprinkle some aluminum sulphate under the shrubs. It’s a hydrangea’s ability to access aluminum that keeps the flowers blue.
Fall pansies are in the stores about now, so you can replenish window boxes and planters with fresh flower colour that will take you through to spring. Also, consider adding heuchera and euphorbia and evergreen ornamental grasses to planters.
Dahlia tubers won’t need lifting for a while yet but you could prepare winter quarters for them and space for other tender items that will need to be brought into a frost-free environment next month.
Edit and delete
Walk your garden and decide which plants can stay and which need to go. Look at each plant and ask: “What have you done for me lately?” If you don’t like the answer, make a change. This process is not just about tossing out unproductive plants; it’s about recognizing that in your enthusiasm you may have overplanted. Doing this will open up new areas and give you a jump on whatever makeover you have in mind for spring.
Whew! Now have that glass of prosecco.
You deserve it.
Steve Whysall is The Vancouver Sun’s
garden columnist. firstname.lastname@example.org