Preparing your garden for fall? Here’s what you need to know

Three local experts share how to make your lawn, side garden or planters healthy and ready for the cooler months in NoVA.

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Here in Northern Virginia, humid summers are something residents are used to. People know how to dress appropriately for the climate, care for their bodies by hydrating consistently and hiding indoors when it all becomes too much to bare. And, when fall rolls around, most of us are more than ready for it. 

The plants in your garden are the same way. While some species are more comfortable with August’s high temperatures than others, every living organism in the garden needs to be properly cared for during the muggy days of August, through the temperature drop at the end of September and beyond.

“Sometimes people are a little bit hesitant of planting in the heat of summer, but I plant all year-round,” says David Watkins, corporate manager of Merrifield Garden Center. “It doesn’t matter if you plant spring, summer or fall, the bottom line is that somebody has to take responsibility for caring for and watering those plants.”

Here, three NoVA-based experts—Watkins, President of J&J Landscape Management, Inc. James Derrington and Meadowlark Botanical Garden’s horticulturist Charles Bruce—share their advice for keeping your outdoor landscape happy and strong for the upcoming fall season.

What are the best methods of care for your plants this time of year?
DW: Watering really is number one, two and three with this. Heat and drought-tolerant plants do the best right now because they bloom in the late end of summer and do well in sunny locations. These are all easy plants to grow, it’s just that you have to make sure they don’t dry out completely. The flip side of that is people sometimes do what I call “loving-death,” where they drown them. We ask that you check on them every few days and water them when they feel dry to the touch.

JD: Gardening and landscape maintenance as a whole is an ongoing process, so this is the time period where you want to keep an eye out. You never want to fertilize grass in the summer here in Virginia; we do that in the fall. It can cause top-growth, meaning the plants only grow at the top of their roots, which is not what you want, you want deep-root growth. But with annuals—plants that perform their entire life cycle in a single growing season—I would recommend fertilizing once a month from spring through about November.

CB: In August, it’s lots of watering when there is no rain. You typically want to be watering your garden so it receives about an inch of water a week. This will help plants develop deep roots so they can still be their best in the August heat. For some of the plants, you will want to be deadheading (removing dead flower heads) to help encourage new flowers and extend their blooming season.  

Why is fall the best time to start harvesting certain plants and vegetables?
DW: A lawn’s happy place is about 50 to 75 degrees. When it is 90 degrees out in the summer, your lawn is way out of its comfort zone and it is suffering. The month of September is really when that starts to change and we can go in and start our fall planting, because the soil and the ground is ready at this time. 

Cool season vegetables are the same. We don’t have them right now but we are starting to prepare for their arrival next week, so that they will be ready for planting when it is cooler at the end of September and beginning of October.

How should people maintain their outdoor spaces during the transition period from hot, long days to cool, shorter days?
DW: Good gardens are always the result of good planning, and August is the time to look ahead for the fall. A lot of people try to eradicate weeds in their lawn during this time, because most plants are going to start blooming in September and October. And whenever you put new plants in the garden, you have to be extremely attentive to the watering because they don’t have established root systems yet, so you have to be even more sensitive to their watering needs.

JD: You’re maintaining your existing landscape in August, which includes making sure the entire area gets an inch to an inch-and-a-half of water each week. When it comes to your plants, I recommend watering them three times a week.

Also in late August, we start over-seeding, which thickens any turf that may have gotten shorter throughout the summer, as well as aeration, which allows moisture and air to get to the root system of the turf. End of August is the ideal time to seed, because you want to do it before the seeds germinate in the cooler months.

CB: For preparing for fall, your gardens should be weeded and mulched about 2 to 3 inches. Here at Meadowlark, we use leaf mulch in the garden beds. This will help keep the soil moist and help to maintain even ground temperatures so your plants will not heave in the winter. The mulch will also help to prevent weed seeds from germinating in the spring. As the mulch breaks down, it will also be feeding your garden bed as an organic fertilizer. 

If you can, I would leave your perennial flower stems up until early spring.  This will allow for birds to eat the seeds in fall and throughout the winter, as well as give our native insects and pollinators a home. If you need to remove spent stems, just cut the stem above the new growth at the base of the plant.


While the month of August is more of a preparation period, there are some flowers that do very well in the moist, end-of-summer heat. For those who have a green thumb, below are a few plants and flowers that will thrive this time of year, according to our experts.

  • Annuals have a shallow root system because their lifespan is so short, and there are several dry-tolerant options, like petunias, sunflowers, zinnias, and salvia.
  • Coneflowers are late summer bloomers that love the sunshine.
  • Love the look of bulbs? Lycoris, also known as surprise lily or spider lily, as well as colchicum autumnale, known as waterlily, are two good choices.

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