Do you think that spring is the best planting time for your perennials? Well, think again, because it is fall! Yes, with the new season, you will be busy sowing and finding a home for veggies and seedlings, but the months of September, October and November are ideal to bring new plants to your garden. Exactly when depends on your climate, and we’ll get to it soon, but you will be amazed to find out how many advantages you get if you transplant now, and you don’t wait till winter is over.
Fall looks like the end of the season, but in reality, “every ending is a new beginning” and if you plant perennials now, they will grow stronger and better when spring comes, and you will have much more time for other chores as well. Let’s see why and how then…
Planting Perennials in Fall – It’s a Matter of Thirst!
Planting perennials in fall means that they will find a new home when rain is plentiful. True, this can happen in spring then, but not everywhere, not always, and then they are faced with a dry period (by summertime) when they are still young!
If you transplant them in fall, on the other hand, they have many months, 6 to 9, of abundant water. And because you need to irrigate young perennials very regularly, this will save you both time and the most precious resource of all.
And if you live in a dry region, planting perennials in the fall is a must!
Plant Perennials in Fall to Avoid Pests
It is true that some pests come back in fall after the sultry days of summer, but… They are fewer than in spring! Just think about how many slugs and snails you se crawling around your garden in April. Do you see as many in October? No…
The humid climate does promote some pests, but the days are getting colder, and – leaves and stems are tougher by now, so they cannot munch on your perennials as easily as in spring.
Perennials Planted in Fall “Sweat” Less than in Spring
…and in summer for sure! Days get warmer and warmer during spring, so, newly planted perennials lose more moisture during this period. On the other hand, if you transplant them in fall, they will not suffer from evaporation as much.
This, of course, means that they can settle in more comfortably. Cooler temperatures allow perennials to develop their root system without heat stress, and this means that next year, come spring, they will be much stronger. They will start off the season with lots of energy and vigorous growth.
On this point…
Plant Perennials in Fall to Start off Early in Spring!
When you transplant a perennial (or any other variety), it takes its time to settle in and then it will start growing. First, it needs to get accustomed to the new soil and place, grow roots, “feel at home”, and only after that it will start new leaves and shoots.
So, if you plant perennials in spring, you will lose aa few weeks of growth, but if you transplant them in fall, they will be ready to start as soon as the new season starts! This can mean more foliage, more flowers, and also more fruits!
Plant Perennials in Fall and Don’t Worry About Weeds (Too Much)
When spring comes, virtually all plants start growing and when they do, they are both hungry and thirsty – including weeds! This means that your beloved daylily or phlox will have to compete with them, and, as you know, “weeds” can grow very fast and take over.
Solution? Just plant perennials in fall, of course! Yes, there are still some weeds around, but they are usually coming to end of their season; they are “tired” and less vigorous. So, it’s easier to control them and they don’t pose a “threat” for your chosen variety.
Fall-Planed Perennials Grow Strong Roots Before Winter
As we know, the health of a plant starts underground… Strong roots mean a sturdy perennial (annual…) If you plant them early enough in fall, they will have time to grow healthy and long roots, so, when winter approaches, they will be perfectly equipped to face that harsh season.
Do remember to mulch though to keep their “feet” warm – we will see it later on.
Planting Perennials in Fall is Cheaper!
Money matters too, doesn’t it? Just compare the price of seedlings in spring and in fall, and you will certainly notice that you will get a much better deal from nurseries and other outlets in this late season…
You see, they follow the market, and because everybody is looking for new perennials for their garden in spring, prices go up. So, be smart – plan ahead and save yourself a few bucks by planting them in the fall!
Plant Perennials in Fall – And Save Time in Spring
Finally, as we said, spring is such a busy time of the year for gardeners that anything you can do beforehand will save you lots of time, including planting as many perennials as you can in fall…
But now, how can you make sure that if you plant your perennials in fall, you do it correctly? On to our second part of the article – the “how”.
Timing Is of the Essence When Planting Perennials in Fall!
If you plant perennials in fall, they will need 6 to 8 weeks to settle in before the soil freezes. So, check out the first day of frost in your USDA zone to make sure their roots will be safe by then. In most temperate areas, this is usually between early September to mid or late October.
Now, there is some flexibility here, because a light frost will not freeze the soil, so, you usually have a week or two of leeway, but make sure that you only take risks if you know the climate of your region well.
What’s more, if you plant them close to a source of heat (like a house), the microclimate there will be warmer.
Good Soil and LOTS of Drainage if You Plant Perennials in Fall
You will need to prepare the soil in advance, like you would any other season, before planting perennials. But in fall, I would pay particular attention to good drainage. The abundant rains to come will keep them watered, but they have a flipside… If the water becomes stagnant, the roots can suffer, lack oxygen and even rot, especially for newly planted specimens, because they are quite vulnerable at this stage.
Location, Location, Location for Fall Planting of Perennials
Of course, choosing the right location is paramount for a perennial’s future health any time you plant it, but in fall it can be a bit more confusing. Some leaves have dropped, on one side, and the Sun is lower on the horizon on the other side.
This means that a spot that may look like it’s in full Sun in October may be in part shade in June, and conversely, a place that looks shady now may be fully sunny in August…
So, choose the location according to what conditions are in spring and summer, not fall.
Water Deeply After Planting Your Perennials
Ok, fall is a wet season in many countries, but don’t expect rainfall to do your job. As soon as you have planted your perennial, give it abundant and deep watering. This will help the soil settle, and it must be done straight away, even if it has rained a few hours before!
Absolutely Mulch After You Have Planted Perennials in Fall
You can get away with not mulching after you plant perennials in spring, but not in the fall. Some varieties are very cold hardy, but you do want to protect their roots from cold when they are new to your garden.
Mulching makes a huge difference to soil temperature, keeping it about 5 to 10 degrees Celsius warmer in winter (and cooler in summer)! This will protect your perennials’ vulnerable roots from frost and even unusual drops in temperature.
Fertilize Correctly When You Plant Perennials in Fall
We are all tempted to give our newly planted perennials a “quick fix” with fast-release liquid fertilizers as soon as we plant them, but this is a no-no in fall. You must use a slow-release fertilizer in this season (granular, compost etc.)
You don’t want to promote vigorous growth at this stage, you want your perennial to focus on getting strong and well established.
Finally, avoid late fertilization in fall. It’s not like in spring, your perennial is not about to grow new leaves and flowers, it is going dormant. It will still need nutrients during winter dormancy, but in low doses, and if you give them a boost late in the season, it may think it’s time to grow, and the frost will damage it, so…
Fertilize your perennial when you plant it, then nothing till spring, when you can feed it a bit more to grow ne duds and shoots.
So, Get Ready for Fall Planting!
Here we go, all you need to know about why and how to plant perennials in fall. Save money, save time, and they will start the new season early and vigorously. Are you ready?
Written By
Amber Noyes
Amber Noyes was born and raised in a suburban California town, San Mateo. She holds a master’s degree in horticulture from the University of California as well as a BS in Biology from the University of San Francisco. With experience working on an organic farm, water conservation research, farmers’ markets, and plant nursery, she understands what makes plants thrive and how we can better understand the connection between microclimate and plant health. When she’s not on the land, Amber loves informing people of new ideas/things related to gardening, especially organic gardening, houseplants, and growing plants in a small space.