Fall Garden & Yard Preparations

Preparing Your Yard & Garden for Fall

It certainly seems way too soon, but time marches on.

Fall is right around the corner, but there is still plenty of gardening left this year, let's make the most of it. Following is some helpful information that will get you out in the garden this fall and give you some tips to be ready for next spring!

fall yard preparation

QUICK Fall prep tips to do in late August / September:


Harvest any fruit or vegetables that are now ripe.


Bird Baths will quickly evaporate or become full of algae growth quick in this summer heat, remember to clean them out regularly and keep them topped up to help our birds during the worst heat spells.


Bees also need water. It's easy to set out water for bees. Fill as shallow tray with grape size gravel and fill. Bees will be able to navigate the tops of the gravel safely while still being able to access the water you have left out for them.


Keep your container plants well watered. Continue to fertilize into fall every couple of weeks or so, to keep them looking their best.


Deadhead your lilies. This will help them produce a better display next year.


Cut back your herbs now. There is still time for new growth and fresh leaves to harvest before frost.


Cut back faded perennials to tidy the borders in your beds.


Deadhead bedding plants and perennial plants to stop them self-seeding and to encourage further flowering into the autumn.


Trim Lavender plants after they've finished flowering and this will keep them compact.


Divide and replant Bearded Iris now. Doing it now will give them time to form roots and flowers buds for next year before the cold weather arrives.


Look out for symptoms of Clematis Wilt such as wilting leaves and black discolouration on the leaves and stems of your Clematis. Cut out any infected plant material and dispose of it in your household waste.


Keep feeding and watering tomatoes. Remove leaves lower down on the plant to help with air circulation and prevent disease.


Water vegetable gardens and fruit plants daily or as necessary in the warm weather.


Once runner beans reach the top of their support pinch out the tips. This encourages side-shooting and more beans at a manageable height for picking.


Plant out any rooted runners of strawberries for a good crop next year.


Hedges can be given a final trim now before they stop growing.


Turn the compost in your compost bin to keep it well aerated and to speed up decomposition.


Keep an eye out for white powdery mildew on plants. If possible, remove the affected parts and spray with a fungicide to prevent further spread.


Take lots of photos of your garden now if you want to rearrange it - it's much easier to do this if you have a reference point.


Think about which bulbs you would like for next spring – soon now they will be arriving at greengate Garden Centres for autumn planting.

Fall Colours:

There are still ways to get some great colours in your gardens:

You can fill gaps in borders with autumn flowering plants such as chrysanthemums to extend the colour to the end of the season. You'll find a good selection in the perennial lot. Continue to feed and dead-head your hanging basket and container plants.They will often keep going until the first couple of frosts. Keep watering and feeding and they will keep blooming into fall. Again, bring them if you have to.

Keep it going!

Continue to water all your trees and shrubs and perennials. It was very dry this summer and it looks like it will be into fall as well, so keep everything nice and moist. Especially newly planted babies. You want the roots to keep growing for as long as possible. Water right up until freeze up. If you can "freeze in" your overwintering plants here in Calgary, that's always a good idea.

If you recall last January,

it was very warm and very windy and dry. Then February hit… hard. It was basically -30 the whole month and that's the kind of weather that can do plants in. Especially cedars and evergreens that were too dry in the first place. You can give your plants their best chance by keeping them nice and moist now right up until freeze up. Even if your deciduous trees have gone dormant and lose their leaves keep the root ball moist so that it freezes right in.

Fall bed preparation:

Digging in soil conditioners such as steer or sheep manure, gypsum, composts or peat moss into your soil in the fall will save you time in the spring.

Think of all the energy saved for next spring's planting. Turn over the soil with a spade; being careful not to tear or disturb any existing roots. Then dig in the soil conditioners using a garden fork. Large lumps should be left in the soil at this point. Frost helps to break soil into a less dense soil structure, ideal for plant growth and moisture retention. Turn again in the spring, shortly before planting and break down large lumps with a garden fork. You can also add a slow release fertilizer for an added boost. Be careful not to walk on the area that has been freshly turned.

Fall lawn preparation:

A little preparation in the fall encourages early spring growth in your lawn.

As the days get shorter and the temperatures drop your lawn will stop growing. Now is the time to mow your lawn for one last time. Set your mower to cut 1-2 cm. higher than normal, mow the entire lawn, apply a slow release nitrogen fall/winter formulation fertilizer, and then water the entire lawn thoroughly. This will ensure an ample supply of nutrients and moisture for early spring growth. If fall turns into an Indian Summer and the lawn dries out, continue watering your lawn until freeze up. Remember to drain outside taps or any items that are stored outside; for example, sprinklers, nozzles, or hoses. These items can be damaged by freezing water. Leaves should be raked off the lawn before any permanent snow falls. If leaves are left on the lawn they will become wet and form tight layers, which can provide ideal conditions for mould diseases. Fall can also be a good time to treat weeds in your lawn as most weeds grow fairly actively in the cooler temperatures. The fewer weeds you end this season with the fewer you will begin with next spring.

By putting some time in now your lawn and garden should be primed and ready to go come spring! Can't wait.


Fall fertilizer applications are important.

The slow release, low nitrogen fertilizer you apply in the fall develops strong roots, which enables grass and plants to over winter well. Fall fertilizers are stored in the root system over the winter and provide nutrients for early spring growth.

Fall Tree Protection:

If there is a prolonged dry period in the Fall it is important to water your evergreens.

Do not water at the trunk of the evergreen because you do not want the trunk wet if and when it freezes. Water slowly and deliberately before freeze up and watch the weather. There may be periods in the winter and early spring where these trees may need to be watered again.

For winter protection of cedars, we recommend that you create a windbreak at least 6 inches away from the plant. This can be created with burlap and heavy bamboo canes. In some areas, this may not be necessary (i.e. eastern exposures) or microclimates created by varying altitudes, and older neighbourhoods where large trees and houses cut down on exposure to that dry West wind known as a Chinook.

Most evergreens we grow are native here and can cope. Spruce, pine and juniper tolerate our dry climate and strange weather patterns amazingly well. Cedars, however, are native to climates where winter is consistently wet and cool. We can't give them that, and many don't survive our winters. Cedars have more chance of survival in climates that stay cold throughout the winter more. They are one evergreen that should be watered periodically until the ground freezes, but don't overdo it! They have a better chance in a shady spot than in direct sun and winter wind.


Overwintering Herbs:

Now that fall is upon us it is time to prepare your herbs for winter, and maybe even bring your herb garden inside.

Hardy perennial herbs, such as chives, sage, tarragon, and thyme, can certainly overwinter if they are planted in the ground, but mulching can help to prevent the freezing and thawing associated with Calgary's winters. A more consistent temperature through out the winter helps to reduce the stress on the plants and will help ensure a healthy plant come spring.

Any herb you can grow in your garden can be brought in to grow and enjoy all winter long. Herbs in pots can be brought at any time before freeze and placed in a sunny location, in some cases artificial light may be needed.

If you did not plant your herbs in pots you can still move them inside by either transplanting full plants into large pots, or taking cutting and starting new plants. Full plants should be potted in a deep container, with good soil and transplant fertilizer, allow the plant time to adjust, and bring plant in before first frost. If you would prefer smaller plants you can take cuttings about 4-6 inches long, dip in rooting compound, and place in small pot covered in clear plastic or covered planting tray and put in a sunny location. Again additional lights may be required.

Care for, and maintain, your herbs through the winter and you will have fresh herbs all winter long and healthy plants to put outside in the spring.


Protect your tender perennials:

Sudden increases in temperature during one of Calgary's Chinooks can cause a plant to break its dormancy and leaf buds developed in the fall can begin to grow.

Then when the next cold snap occurs, it can't go back to being dormant again, causing serious stress or killing leaf buds. The plant would be fine during continuously cold weather but now it's stressed. The goal of protecting your perennials is to minimize the impact of Calgary's fluctuating weather.

Many of our perennials, shrubs and trees are cultivars of our native plants, so they are hardy here. The native ones can also suffer the same fate but are usually adaptable enough to come back. There is little we can do to prevent this type of damage on trees and shrubs, but mulching over the root area of perennials can keep the roots cold a little longer and lessen the chances of untimely leaf bud growth. Dry leaves and other fall plant debris make good mulch; compost and vermiculite can also be used.

Plant hardiness is expressed in zone numbers - the lower the number, the hardier the plant is. Calgary is generally considered to be zone 3-4. If you like challenges, some zone 5 plants can survive if covered with mulch and then a cloth cover such as burlap, held down with rocks to stop the mulch from blowing away during our Chinook winds. Snow is a good insulator and helps to keep plant temperatures more consistent. Click to see a zone map.

Hybrid tea roses

may require some protection to survive our unpredictable winters. In the fall when they have had some frost, prune long stems back to about 12-18 inches. Give them water occasionally during a warm fall, as they are still not dormant and often still have green leaves. Do not cover too soon, as that will prevent the plants from exposure to cold, which is what signals them to become dormant. Before an expected hard frost, cover the plant with a Styrofoam rose cone with the top removed. Fill the cone with dry, well-packed leaves, vermiculite or straw and cover the opening with cloth, held down with rocks, or bricks, which allows air circulation during Chinooks. Uncover in spring when poplar trees are leafing out. Uncovering them too soon to see if they are alive may expose them to the next hard frost. Snow is an excellent insulator and may be piled on covered tender roses for added protection. Click for for information.

tea roses

Any extra protection that you can give to your tender plants can help them to make it through the winter. With a little bit of thought, care, and of course, work in the garden you can help your plants, not just make it through the winter, but thrive in the spring.

Dividing perennials

Perennials are not maintenance free. In addition to staking, watering, and fertilizing in preparation for winter, some perennials will also require dividing when they outgrow their spots and for some perennials fall is a great time to do this. Click for for information.

dividing perennials

If the flower quality and quantity drops in your mature perennials this may be a sign of overcrowding, and they may need dividing. Some may simply have outgrown the place they are in or other plants, as they grow, may be creating too much shade for sun loving perennials. Many perennials form clumps of stems. These stems are actually individual plants with their own root systems. Perennials cannot be divided if they grow from one central stalk. Early blooming perennials should be divided in early fall. When all the leaves have fallen, gently dig up the plant and separate the roots of the individual clumps to be removed. Replant the removed plants in an appropriate place in the garden. Later flowering perennials should be divided in the same way in the spring, as soon as they are showing growth.

Delicate tubers, such as Dahlias, can be dug up from the garden for use next year. These tubers may grow into clusters that can be separated, increasing the amount of tubers you have for planting in spring. Remember it may take a couple of seasons before your tubers are ready to be separated. When separating its important to ensure that each tuber has a portion of stem on it. Plant again in spring normally, according to your local seeding schedule. Tulip bulbs cluster and can be treated in the same way.


Dividing perennials, when necessary, will improve the overall health of the plants, by giving them the room they require to grow into healthy plants. It will also give you the added benefit of increasing the amount healthy, desirable, plants in your garden, which is never a bad thing!

Any perennial that is showing signs of dying out in the middle of the clump is a good candidate. This will keep your plants healthy and vigorous year after year and of course you will have more plants to share or move around in your garden.

Clean your ponds of leaves and debris. Fall seems to be the busiest time with blowing and falling debris. Keep it clean and keep it going! A little bit every week will help you keep ahead of fall.

Clean out cold frames and greenhouses get ready for fall cold weather crops.

Continue to feed and deadhead hanging baskets and container plants many of these plants either annual or perennial will keeps going strong, sometimes even past the first frost.

Keep deadheading annuals and perennials to extend their performance.

Deadhead your dahlias and roses to keep flowers coming. Be ready to dig out bulbs like Dahlias and begonias. You can keep them overwinter in a cool dark place.

Keep harvesting crops. Anything that is now ready to be harvested should be. Frost can come at any time in September, or not at all. Be ready.

Pull or cut off the foliage of main crop potatoes three weeks before harvesting them. This can prevent blight spores and help to firm the skins of the potatoes.

Spread newly dug potatoes out to dry for a few hours before storing them in a cool, dark place. You can store them in paper bags, as this will allow the crop to breathe while it's in storage. Store only undamaged, disease-free potatoes.

Help pumpkins ripen in time for Halloween by removing any leaves shadowing the fruits.

Raise pumpkins and squashes off the ground it will help in the prevention of rotting. Use slate or wood.

Keep feeding and watering beans to make the most of them. Harvesting often in smaller amounts to prevent them from going to seed.

Start the autumn cleanup. Remove any old crops that have finished and clear away weeds to leave your plot ready for the winter.

In the fruit garden:

Tidy up your strawberry plants and clear away any used straw.

Pick ripe apples. When they are ready to harvest they - they should come away easily.

Pick off rotting fruits from pear, apple and plum trees - they will spread disease if left on the tree.

Mow long grass under fruit trees to see fallen fruit easier.

Cut back the fruited canes of your summer raspberries and leave the new green canes for next season. If it's possible support next year's raspberry canes to wire, fencing or trellises.

In the greenhouse:

Water greenhouse plants early in the a.m. so the greenhouse is dry by the evening. Damp, cool nights can encourage disease.

In the evening close greenhouse vents and doors late in the afternoon to trap in heat overnight.

Empty your finished pots. Dead plant material can hide unwanted pests through winter.

Clean out your greenhouse by clearing out fertilizers and other items that can't be frozen. Clearing out old and unused debris can reduce the risk of pests and diseases next year.

Remove shading from your greenhouse towards the end of the month. The days will be getting much shorter.

Lawn care:

Fill bare spots or create new lawns from turf or seed - autumn weather is favourable for good lawn establishment.

Raise the height of your mower blades as grass growth slows down.

Apply a fall fertilizer this will give your lawn a head start next spring.

Other jobs about the garden:

Improve clay soil with compost before it becomes too wet or frozen.

Create compost bins. Fall leaves and rotting plant materials make for great compost. Be ahead of the weather.

Raise pots off the ground for the winter and store pots that are not suitable to be outside in winter.