Fall Gardening in Zones 7-9: A Comprehensive Guide

Winter is coming, but there’s still time for one last hurrah in the fall garden

Zinnias still blooming in the pumpkin patch in early October

It’s early autumn and what remains of the summer garden is out of control and looking tired. Leaves are starting to look dry and going brown. The big box stores have had their Christmas displays up for the past two months.

All of them are signs there are just a few months left until the chill of winter.

Fortunately for those of us living in the southern half and coastal United States – USDA zones 7-9 – there’s still plenty of time to grow another round of vegetables as well as do a little garden prep for next year before it gets cold and ugly outside.

If you’re lucky enough to live in one of those zones, here’s my guide to what you need to know, and the things you can (and some that you should) be doing in the garden this fall.

Growing fall vegetables and flowers

Yes, it is possible to grow lots of different veggies and flowers in the fall. And no, you don’t have to do a lot of extra work or anything particularly special to do it.

When extending your garden into the fall, the main thing you should keep in mind is when you typically see the first overnight frost. This can vary a lot. Depending on where you live, it might be as early as early October, or it could be as late as January. Either way, you should know it because that first frost is going to kick off a cycle that can bring your garden to an abrupt halt unless you’re prepared.

What to Grow in Fall

Lettuces and Spinach are ideal for fall growing

Now that summer’s over, a lot of the cool season annual flowers and veggies from spring will do just fine in fall as well. Good choices of vegetables for a fall garden are generally leafy members of the beet, cabbage, carrot, and lettuce families, including:

Flowers that will bloom in fall include:

When it comes to choosing plant varieties, you’ll want to choose ones that mature or bloom in 65 days or fewer. If you’re lucky enough to live in an area where the frost doesn’t get there until winter begins (or later), then you can pick varieties that take up to 80 days to mature.

Direct Seed versus Transplant

Brassicas and lettuces ready to transplant into the garden

For vegetables, if your days are still warm in early fall and your first frost doesn’t come until November, you can direct seed a lot of your crops because the important thing is soil temperature. Warm soil encourages the seedlings time to sprout and get established before cooler temperatures set it. You can also keep the soil warm for a longer period with a good layer of mulch to act as a blanket early on.

If your frosts are earlier in the season, or you’re planting flowers, it’s probably best to use transplants. Transplants basically give you a four-to-six-week head start versus direct seeding, so they’re much more likely to make through any unfavorable weather than seedlings.

Any decent garden center or nursery will have a fairly good selection of young vegetable and annual flowers ready for transplanting. But, if you’re looking for veggies and flowers a little more exciting than those grown for retail shops, check your local farmer’s market. I’ve found they’re great venues for local growers with all kinds of interesting plants selected specifically to grow in the area.

Fall Garden Location

With the days getting shorter and the sun lower in the sky, certain areas of the garden aren’t going to be as suitable in fall as they were in summer.

The sun’s lower angle means areas in full sun during high summer might be shaded by shrubs, trees, or buildings for a good part of the day. With the days shortening, those areas won’t just receive less intense sun, but they’ll have fewer hours of it as well. That leads to colder soil conditions, and plants will struggle.

In fall, use garden beds that will be in full sun for 6 or more hours

Fall plants will do best in areas that receive at least 6-7 hours of direct sunlight (the equivalent of 4-5 hours of summer sun). Heat absorbing structures like brick walls, the side of the house or shed, are also good places for fall gardens – especially if they face south or west.

If the bed doesn’t meet the sun and/or warm wall minimums, let it idle through the winter. It’ll get a chance to rest and you won’t be fighting nature trying to get something to grow there.

Pots are also a good choice for fall gardens. You can move them around (even indoors) and keep them warm and watered more easily than plants in the ground. I’ll often have a few pots of plants I want but don’t need a lot of (dill or cilantro, for example), that I keep near the house. In the morning, they move into the sun, in the evening they move back to the warm, stucco wall.

Garden Bed Cleanup and Preparation

Whether you plan on using one of your garden beds from summer for the fall, or you’re going to let it rest until spring, you’ll still want to clean it up before the weather gets ugly.

Clear Garden Beds

The first thing is to remove the stakes, trellises, poles and other plant support structures. If you use soaker hoses or drip irrigation, clear those out of the beds too.

Once the beds are cleared of infrastructure, cut the leftover and spent plants to the ground and send them off to the compost pile.

Tip: When clearing spent plants from a bed, don’t remove the roots unless they’re weeds!

The function of roots is to pull nutrients and water from the soil and, in many cases, store those nutrients until the plant needs them. For example, you’ve probably heard that beans, peas, and other legumes “fix” nitrogen in the soil. They do that by pulling nitrogen from the air and storing it in root nodules. So, if you pull the roots along with the plant, you’re actually removing nitrogen that the next plants you put there could use.

Once the beds are cleared, if you’re going to let the bed lie fallow for the winter, just rake the soil to even it out and it’s done.

If it’s a bed you’re planning on using in the fall, rake the mulch (if any) up and put it off to the side. Then add fresh compost, manure, or fertilizer (I’m a fan of composted chicken manure) and till it into the bed.

Gaucho the Rooster helping me move chicken manure to the garden

Loosen and Aerate the Soil

Make sure the bed is well aerated and any big dirt clumps have been broken up after tilling. The summer growing season removes a lot of organic matter from the soil leaving higher concentrations of rocks and minerals that compact and prevent air and water from penetrating. Beneficial soil microbes and critters need air and water to survive, so you want to make sure the soil is loose and has plenty of gaps to trap it. (You can read more about what healthy soil is made of here.)

After your bed(s) have been amended, you can re-lay your irrigation, put any mulch back in place, and the bed is ready for planting.

Tip: Even if you don’t normally mulch your beds, you should in fall.

Dry leaves are plentiful in the fall and make a great mulch that will help conserve water and insulate the beds throughout autumn and winter. By the time spring rolls around the mulch will have decomposed to the point that you can till it into the bed, adding lots of carbon-rich organic matter that’ll give spring plantings a quick start.

Fall Garden Care

Pest Control

The nice thing about gardening in the fall is that you won’t have all the problems with pests that you do in spring and summer. Most insects will be gone (or close to) for the season, but you can still have problems with birds and rodents — particularly mice, squirrels, and rabbits, all of whom are active year-round and love to add fresh greens and veggies to their fall diet of mostly seeds and nuts.

The best control for rodents is a “tea” made with hot peppers and water. Spray it on the leaves and stems of your plants and after a single nibble, they’ll leave them alone.

Applying the rodent repellent tea with a garden sprayer

Sadly, hot pepper spray doesn’t work on birds because they can’t taste the heat. But I’ve found the physical deterrents like noise makers, flashy, metal streamers, and dummy predators (plastic owls, giant eyeballs, snake silhouettes, etc.) work – at least for a while.

If you find the birds aren’t being spooked by the deterrents after a while, try moving them to a new location in the garden. Birds don’t like change, so the same plastic owl that didn’t scare them in one place will in a new place – at least for a while.

Disease Control

Soil-borne fungi like fusarium and rust are more difficult to control because they’re widely adapted to different environments and can easily survive winters in zone 7 – 9.

Fusarium, which causes wilt, can be controlled (not eliminated, but controlled) with baking soda. Till dry baking soda into the soil around the plant’s base to control the spores in the soil. Make a water-and-baking-soda-spray to apply to plant leaves and stems.

Rust is a tougher one as most biological (organic) controls don’t work. You can apply a fungicide, but they’re often ineffective, not to mention toxic to people and pets.

The best control for rust is the removal and disposal of the infected leaves and stems. Don’t try and compost infected plants as the spores on the leaves can survive composting and will travel to other plants given the opportunity.

Frost Protection

Dry leaves are plentiful in fall and make a great mulch to keep garden beds warm

If you’re in an area where frost is a threat, make sure your soil has a good layer of mulch to protect the roots. If you don’t have any mulch handy, burlap landscape fabric also makes a good blanket.

Most of your thicker leaf and fall root crops (e.g., cabbage, kale, carrots, radishes, etc.) will get through a few frosts without additional protection just fine. But tender plants like lettuces and spinach will need some shelter.

Floating row cover will provide good protection from light frost. If your frosts are heavier, extended, or get down to a hard freeze (i.e., below 30° F), you’ll need to provide more substantial protection via structures like hoop houses, low tunnel row covers, or flexible polycarbonate sheets.

If you’re in USDA zones 7 or 8b, these protections will help extend the growing season through fall and sometimes into early winter. If you’re in the warmer zones 8a and 9, it’s possible to grow throughout the winter too. Where I live in San Diego County (zones 9a and 9b), we have lots of farm operations and those low row tunnels are a common sight in the fields in winter.

Garden maintenance

One of the other advantages to gardening in the fall is that weed control is nowhere near as big a task as it is in spring and summer. Things grow more slowly in fall, so keeping on top of the few weeds that do crop up is pretty simple. A once a week weed clearance is usually more than enough to keep the garden clean and tidy.

If you have a compost pile (and why wouldn’t you), the one thing to keep on top of is making sure the pile is turned regularly. In the summer it’s warm and there’s plenty of biological activity to turn that dead plant matter into compost without a lot of work.

My compost inspection crew checking my work in the compost bins

In the fall and winter, however, activity slows down and so it becomes necessary to turn the pile more often to keep the compost critters happily working.

Additionally, a compost pile, with its warm center and protection from predators, becomes a nice spot for rodents to set up a homestead and ride out the winter in relative comfort. Turning your compost more often keeps that from becoming an issue. It also ensures that you have plenty of rich, ready compost come spring.

Conclusion

So there you have it. If you’re in USDA plant hardiness zones 7 and higher, it’s perfectly possible to enjoy a lively garden and fresh foods all the way into winter (and even year round).

All you need is to take the few simple steps detailed above, and your fall garden will be a striking success.

Happy growing!