Ah, fall: when cozy sweaters come out, the air crisps up, a kaleidoscope of colorful leaves decorate sidewalks, and it’s a struggle to decide which pumpkin-flavored drink to buy at the local coffee shop. In the garden, grasses turn tawny, flowers transform to seed heads, and it’s a struggle (as you sip your pumpkin-spiced latte) to decide what needs to be done and how to prepare plants for the coming sleepy, cold months.
You’re on your own picking your hot beverage of choice, but we can help you figure out your fall gardening chores. Below, six burning questions you may have about autumn gardening.
Featured photograph by Christin Geall, from Flower Design: A Week at the Cambo Estate in Scotland.
Do you still need to weed?
Yes. (And sorry!) We may not always see weeds, but trust me, they’re there, quietly resting below the soil surface, waiting for us (or creatures) to disturb the soil so that they can get some sun and a drink of water—and then KABOOM! Total weed invasion. Fall is definitely a time when weed seeds are storing food for winter, or they are exploding as they dry up. My advice: don’t procrastinate. The best way to get ahead of a spring weed invasion is to get a hold of the situation in the fall. And the most important thing you can do right now is prevent weeds from going to seed. How? Remove the weeds you see. And to ensure a successful eradication, determine what weeds you have and how they reproduce. Do they spread by seed, by rhizome, or re-sprout with a deep taproot? Once you know your culprits and how they make more of themselves, then you can learn how to successfully attack them. (See Weed Wisdom: What 10 Common Weeds Are Trying to Tell You.)
Here’s an idea to prevent weeds from taking over your world: lay down a 3-inch thick layer of mulch to bury newly dropped weed seeds and prevent light from reaching them. For large weedy areas, consider the sheet mulching method where you lay down flattened cardboard or newspaper first and then pile a thick layer of mulch on top. For individual weeds, consider pouring undiluted vinegar directly on the weed. Whatever method you do choose, manage weeds as naturally and as non toxic as possible. (See Landscaping 101: Pros and Cons of Homemade Weed Killer.)
When can you stop watering plants?
Bottom line: don’t stop watering yet, because plants still need water—just not as much as in the hot summer. After plants spend the summer devoting time and energy into leaf and flower growth, they move on to fruit and seed production, and then they take advantage of the fall season to get busy growing their roots. This means if we have a non-rainy fall, plant roots can dehydrate and plants become stressed; they will need continued drinks of water to keep them healthy. This is especially true for sunnier south-facing areas, and not so much for north-facing areas where the moisture will stay longer. Also, remember that plants under solid eaves don’t benefit from rainfall and can remain dry as a bone so you will need to hand water these areas.
Pro Tip: Newly installed or transplanted plants definitely need regular watering through the fall.
When winter finally creeps in, it also brings along its own set of dry, damaging conditions. When plants are packed under snow and ice, roots still get thirsty. The solution is to super hydrate plant roots before winter, and before the ground freezes, this means giving your plants long, deep soaks of water. When temperatures start to drop below 40 degrees F, you can wind down the water. If you’re in a warmer climate, the soil may not freeze at all, and if it doesn’t rain for a few weeks, your plants will still need a weekly dose of H2O.
Pro Tip: Water plants in the morning to give the soil time to soak in the watery goodness before temperatures drop in the evening. (See Your First Garden: The Right Watering Method for Your Garden.)
What plants need to be cleaned up and pruned back in the fall?
The general rule is that as long as your perennials look lovely, leave them alone. As the season shifts into winter, some plants might get hit by a heavy frost and die back, but others will stand strong, add visual interest though the doldrums of winter, provide shelter for animals and insects, and, via their dried seed heads, offer crucial food for birds. Besides, foliage (even passed its prime) helps a plant retain moisture and provides a bit of insulation.
That said, certain plants do need a good haircut in the fall, and those are plants that insects or diseases have attacked. In this case, cut back these plants and dispose of the diseased matter into the trash and not the compost pile to avoid possibly promoting the problem again.
Pro Tip: I live in mild Northern California and I especially like to cut back raggedy-looking daylilies and spent summer blooming salvias in the fall. I do, however, leave alone ornamental grasses (for birds to shelter in), Rosa rugosas (for the winter rosehips) and Echinaceas and Rudbeckias (for the seed heads).
How do you prevent squirrels from digging up spring bulbs?
Did you know that a squirrel’s favorite fall activity is actually watching you plant bulbs? These pesky critters patiently watch and wait, knowing that as soon as you leave, they get to indulge in a bulb-feasting fiesta. Plus, this is the time when their food sources wane and they go into panic hoarding mode. The solution? Protect your newly planted bulbs by covering the area with either chicken wire, hardware cloth (it’s like chicken wire but has a smaller grid) or plastic garden netting. Make sure to stake the netting or wire down with U-shaped landscape stakes or medium sized rocks. Lastly, cover the area with shredded leaves, mulch, or compost to hide the wire. And don’t worry, your flower stems will still emerge through the wire and mulch but the bulbs will be protected.
You can also consider adding bulbs to existing garden beds so that sneaky squirrels have a harder time sleuthing out your bulbs among your shrubs and perennials. And have you ever heard of red pepper flakes as a natural repellent that’s effective against squirrels? A liberal sprinkle of red pepper flakes over planted bulbs can do an excellent job of discouraging hungry squirrels from digging.
Squirrels are very fond of some bulbs, such as tulips and crocus, but there are other spring bloomers that they don’t particularly enjoy like alliums, hyacinth, muscari and daffodils.
The last idea is to wait on your bulb planting party. The squirrel and chipmunk feeding frenzy peaks in early autumn, but begins to quiet down a bit by late October when these creatures have already stored away most of their winter supply. This means, if possible, plant your spring-blooming bulbs later in the fall.
What other chores need to happen in the fall?
Embrace the fall season with planting gusto because the weather has cooled, the soil is still warm and workable, and winter rains are hopefully on their way. This means it’s the perfect time to transplant plants, plant trees and shrubs, divide crowded perennials and grasses, and plant any natives. Ideally, trees and shrubs need about 6 weeks to establish their root system before a heavy freeze.
Now is also the time to rake up any fallen leaves, put them in a pile and run them over with a mower or put them in a shredder. This leaf mulch can now be spread around your garden or added to your compost pile. The beauty of this free mulch is that it helps suppress weeds, insulate plants when the cold weather hits, and enriches the soil as the leaves break down.
Last, if you live in colder climates, now is the time to refresh your mulch or add new mulch to newly planted perennials, shrubs, and trees. These not yet well-rooted plants might have their root balls heaved out of the ground during winter’s notorious freeze/thaw cycle. Mulch will help keep the soil at a consistent temperature.
For more on fall gardening chores, see: