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August may be the dog days of summer, but gardeners know it’s time to both enjoy the last summer’s blooms and ensure they come back next year. (Photo courtesy of White Oak Farm and Gardens)

Nature has her ways of letting us know when the seasons are in transition. The tree frogs are out, the katydids are singing. The roadside wild flowers are in late cycle — now lined with Queen Anne’s lace, goldenrod and milkweed. And maybe your garden is slowing down, too.

As we start thinking about fall’s arrival, prepping your plants should be high on the to-do list. Here are a few local pro tips from South Fork and Shelter Island pros for making the transition. 

With over 50 years in business, the folks at Marders have great gardening advice. (Photo courtesy of Marders)

Marders, 120 Snake Hollow Road, Bridgehampton, 631-537-3700

At Marders, a mainstay for East End gardeners for nearly 50 years, staff horticulturist Paige Patterson says one of the biggest mistakes gardeners make this time of year is “thinking they can’t plant now – they think they have to wait until fall.”

But, she says, “Any plant is happier in the ground than above it. The sooner it’s in the ground, the better chance it has of establishing its roots before winter.” If you don’t want to wait until spring for a redesign, Patterson says you can dig up and move things around in the fall, but advises waiting for the leaves to drop and the plant to go dormant — and wait for a cool, overcast day.

Patterson, who also teaches classes at Marders, says “ignore a lot of what our old garden books say to do. … I no longer cut back most trees or shrubs in the fall. I deadhead and cut out diseased and damaged branches but my fall pruning now happens in February and March.”

That said, she noted that late fall/early winter pruning is a good time to see what a tree or shrub looks like without its leaf cover. “You can easily see structural problems and where corrective pruning is needed.” She advises against heavy pruning on spring flowering plants, which will suffer and not produce blooms if we experience a warming and frosting cycle as this year. Her go-to tools: FoxFarm’s Bush Doctor “Kelp Me Kelp You,” a liquid seaweed product to cure much of what ails your plants — especially the post-transplant droopies, and the Wilcox All-Pro (No. 251) serrated trowel. “I’ve had it for 30 years and it goes everywhere with me,” she says. 

Sag Harbor Garden Center, 11 Spring St., Sag Harbor, 631-725-3345

“When we think of fall, we think of falling leaves, but there are so many things to do in the garden,” says Linnette Roe, a former professional ballet dancer who, after 20 years of working in nurseries, decided to open her own. At the Sag Harbor Garden Center, Roe, a horticulturist with a bend toward garden design, says ‘tis the season to plan your bulb garden. Trained in natural pest management, which usually focuses on insects but also can include birds and ground animals, she recommends planning your spring garden with bulbs of deer resistant plants. “They are super deer, eating things they never ate before,” she says.

For protecting vegetable and flower beds over the winter, in addition to mulch, Roe leaves a bit of leaf clutter to harbor beneficial insects. For the rest of the leaves, she recommends helpers from LeafEasy — a chute insert that keeps leaf bags open while you rake in or deposit lawn debris. For reaping benefits now, she says it’s not too late for broccoli and kale, vegetables that like chillier temperatures. When planting fall crops, she advises using clean pine straw to retain moisture and moderate soil temperatures. Roe offers classes at the garden center on topics such as pollinators, garden cleanup, deer control and other troubleshooting. 

White Oak Garden Center in Shelter Island is a popular spot for solid gardening advice and beautiful plants. (Photo courtesy of White Oak Farm and Gardens)

White Oak Farm and Gardens, Shelter Island, 74 N. Ferry Road, Shelter Island; 631-749-5814

“This is the time of year for tidying up the garden, especially if you have spring-blooming plants that are looking the worse for wear,” says Phoebe Clark, White Oak’s garden center manager. Her motto: “If it’s brown, cut it down.”

“If you have herbaceous perennials – not woody in the winter — the second they start to look bad, you can cut them all the way to the ground.” For hydrangea lovers, she advised just pruning for shape and save the more serious trim for spring. The cuttings from your trims — peonies, day lilies and non-molding leaves and branches — are perfect for compost, she says, advising gardeners to take care to avoid mixing in anything that has mildew.

If you want to encourage seeding, once the seed head goes totally brown, you can hand spread the seeds. “That encourages plant spread [if you want it] and also gives some to the birds for feed,” she says. This year, the caterpillars are coming out later, so Clark advises doing a leaf check and using a Bacillus thuringiensis (B.t.) organic spray that targets the crawlies. (But, leave the caterpillars on milkweed because they’ll turn into Monarch butterflies.)

Phoebe Clark of White Oak Garden Center says to leave any caterpillars you may find on milkweed, as they’ll turn into Monarch butterflies in your garden. (Photo courtesy of White Oak Garden Center)

It’s also a time to check on your infrastructure — a deer fence if you have one. Walk the perimeter and check for any places of compromise and that the posts are secure. When looking ahead for next year, she says much of the area has “turned into a drought garden, so when planning, I tell people to choose species that can handle those conditions,” she says. Similarly, she advises people to consider native plants, which are lower maintenance and require less water, care and additives. On her list: cone flowers, black-eyed Susans, swamp hibiscus and Joe Pye weed. 

Hampton Nursery & Landscapes, 205 Montauk Highway, Hampton Bays, 631-728-1160

At Hampton Nursery & Landscapes, horticulturist Jill Williamson says August is a time for both enjoying the last of the summer flowers and ensuring they’ll come back next year. “Most annuals will continue blooming and stay okay until it gets cold,” she says, advising that plants will still need ample, deep watering in the August sun. Regularly deadheading flowers will prolong their bloom season. But when plants are thriving no longer, she says pull out the old annuals and cut the perennials to the ground.

Native plants like cone flowers, black-eyed Susans, swamp hibiscus and Joe Pye weed are low maintenance and require less water, care and additives. (Photo courtesy of White Oak Farm and Gardens)

One size does not fill all when it comes to hydrangeas, she notes. “There are certain types of hydrangeas that need to be pruned in spring, not fall, or you cut off the blooms for next year.” She advises checking the plant varieties online for a pruning schedule, and don’t fertilize in the fall. “A lot of gardening is trial and error,” she adds. Other fall to winter tips: a good hay-free mulch to add a layer of insulation and help conserve water. She also likes woodchips: “They don’t breakdown as quickly, so they will stick around a little longer.”

Williamson is among the many horticulturists who give plants and shrubs a dose of either Plant-Tone, an all-purpose organic plant and shrub food or Holly-Tone for acid-loving plants, both of them slow-releasing foods. Also check on any shrubs that are susceptible to winter burn, such as boxwoods. Finally, she says, don’t forget to detach your garden hoses from the spigot, drain them and shut off the water to the outside spigot.