September Garden Tasks
After a cool wet spring we have been rewarded with a lovely warm September in the garden. There are still lots of flowers in bloom even though some seem to be fading. As we head into cooler night time temperatures it’s only normal for plants to start declining. It’s time to start your garden cleanup if you haven’t already. I must admit I hate this part of gardening. It’s sad to see the flowers and vegetables go but it won’t be long before we meet again.
Annual flowers may be leggy or going to seed now. These can be removed and composted and you can add some fall flowers to your containers. I like adding pansies and violas to the garden in September. Planting now means they have time to establish roots before a first frost arrives and a better chance of returning in spring. Think about adding perennials such as dwarf conifers, grasses, Heuchera, dusty miller or ornamental kale to your fall containers for a fresh fall look. Use perennials that you can plant in the garden once they have outgrown your container. I get asked all the time if you should change out the soil in your fall containers. If you are planting a permanent tree or shrub I would change the soil completely. Those plants could be in the container for years and need a good start. If you are planting perennials I would amend the soil by removing at least half the soil, adding new soil and fertilizer. Add leftover container soil to your garden or compost. I completely change out the soil in all my containers every second year.
Now is the time to shop for spring bulbs while they last. With everyone staying at home I’m sure they will sell out quickly. I love spring bulbs as they are one of the first signs of spring. You can plant them in the ground, in raised beds or in containers. Bulbs need a cold period in order to bloom so if you live in an area with warm winters check with your garden centre on how to pre-chill your bulbs. In containers, bulbs can be layered by planting the narcissus as the bottom layer, then some tulips and smaller bulbs like crocus near the top. The bulbs that go on the bottom are the ones that are planted the deepest and ending with shallower planted bulbs towards the top.
Our west coast summer started in July so many of our tomato plants are late to ripen. It’s time to bring in all the tomatoes that are showing some colour to let them ripen on the kitchen counter. I noticed that since the nights have cooled down the cucumber leaves are looking a bit yellowed. Realistically they won’t be producing any new fruit at this point but any larger fruit should ripen if we have some warm days. If you haven’t planted some cool season crops like lettuce, kale or spinach check your garden centres for seedlings. Here on the west coast they can often be overwintered and provide an early spring crop. I place a floating row cover over my beds of salad greens if a frost is in the forecast and the cover stays on all winter. Plants stop growing in the winter when it’s too cold so you’re basically just trying to keep the roots alive. By March the plants start to grow again allowing you to harvest early in the season. Some vegetables have more flavour if they go through a bit of frost. Plants such as kale are best harvested after a light frost. If you are cleaning up all your vegetable beds be sure to mulch the bare soil with shredded leaves. We run the lawnmower with the bag attached over the leaves on the lawn and place them on our gardens. The worms and overwintering insects will love you for it. The leaf mulch will conserve the soil, add nutrients, protect plant roots and provide a home for overwintering insects.
Redesigning the Garden:
I find that fall is a good time to reflect on what’s worked and what hasn’t in the garden. How was your soil this year? Does it need amending? How did your plants do? Are there some plants that you won’t grow again or did you have some successes worth repeating? Do you need to add more garden space? Fall and winter are good times to plan and sketch out next years garden. Take time to look at garden design magazines or Pinterest boards to find ideas.
In the Greenhouse:
September is the perfect time to bring tender plants in the greenhouse or home. You want to try to move plants inside when temperatures are the same outside as inside. A few degrees cooler won’t hurt but if you wait until October they may drop their leaves once inside. It’s the same as when we place our annual plants outside in the spring. Plants need to be hardened off to adapt to a new environment. Check your tender plants for pests before bringing them inside. Gently wash off the foliage and repot into fresh soil before bringing them inside. This will help prevent unwanted pests. Check your greenhouse heating system to make sure it’s working, clean and store pots for next season and order plant labels and seed starter mix for winter planting.
Cleaning the Flower Garden:
Once you have all your containers tidied up it will be time to work in the flower beds. Remove annual flowers that are finished so you have room to plant spring flowering bulbs. There are many thoughts on whether we should cut back perennial plants in the garden. I tend to leave some standing for winter interest but cut down other plants. Plants like shasta daisies have hollow stems and many beneficial insects overwinter in hollow stems of plants so you may want to leave part of the stem in the garden. I leave all our Hostas to decompose on their own. Remember, all plant debris turns into soil and is good for the garden as long as the plants are healthy. September is also an ideal time to add new perennials and shrubs as the weather cools. This month we planted a new garden full of shrubs and topped it off with a colourful display of pansies.
Save Your Leaves
Be sure to save your leaves as they fall to the ground. I know I already mentioned this above but it’s worth repeating. Shred them by running the lawnmower over them and adding them back to the garden. Shredded leaves break down into leaf mold which adds nutrients to the garden, prevents soil loss, protects plant roots and provides a home for overwintering beneficial insects. I top off all my raised vegetable beds with leaves each fall. It’s important to reuse what mother nature gives us instead of placing our greens at the curb and buying them back as soil the next year. In spring the leaves will have broken down even more and you can plant seed directly in the garden without the leaves hindering growth. If you don’t have room for all the leaves in the garden, store them in an empty compost bin or heavy duty plastic bags. I always wish I had leaf mold to use as mulch in the dry summer months. This year I will save some for sure.