Fall is a benchmark time to care for North Texas gardens. Here’s what you need to do.

There are several watershed times on the gardening calendar — benchmarks when some tasks must be completed and when others can finally be started. The boat is leaving one of those docks right now. I’ll explain as we depart.

Fall feedings

Turf experts will tell you that the fertilization you make now will be the most important one you make all year, and it needs to be made in the next 10 or 12 days. It will give the turf one last burst of growth before winter, but more importantly it will add vigor through the cold and into next spring. You want to apply an all-nitrogen lawn fertilizer that has 30 to 40%, perhaps even 50% of that nitrogen in slow-release form. That’s actually the same recommendation you’ve been seeing here all season long, so the product you choose doesn’t have to say “Fall” on its bag. It just needs to meet those important criteria.

Use that same fertilizer for shrubs, shade trees, groundcovers and vines. One of the few exceptions would be if you have acid-loving, spring-flowering plants such as camellias, azaleas, gardenias, wisterias or Carolina jessamines you should apply a specialty plant food intended for them. It will be higher in phosphorus (middle number of the analysis), and it will contain iron and a soil acidifier with sulfur.

Irrigation

This seems like the old hymn we were singing all summer. We got a brief respite with the rains a couple of weeks ago. Our plants greened up and it’s been amazing to watch them grow. But now we’re back in the dry times. This week’s warmth has caused many to go back into the need for water. Don’t put the hose away just yet. Soak your turf periodically. Shrubs should be watered to a depth of 10-15 inches. Patio pots and hanging baskets will dry out every couple of days.

Prune

Remove dead and damaged branches from shade trees. It’s amazing how many trees that were killed by the cold in February 2021 are still left standing in front yards here in North Texas. They’re starting to drop large limbs. Entire trees are toppling. Have a certified arborist take down hazardous trees and limbs before it’s too late. It’s best to have it done now while it’s easy to distinguish good limbs from weak ones. Once they start losing their leaves it becomes much more challenging.

Tidy up your perennial gardens

Remove dead leaves and spent flower stalks and stem stubble. Get rid of weeds, either physically or with herbicides, then mulch the garden with 2-3 inches of shredded, freshly fallen tree leaves to keep winter weed seeds from sprouting. Mulch will also help your soils retain moisture.

Dig and divide perennials

If perennials bloom in spring or summer, they are divided in fall. Fall-flowering types are divided in late winter or very early spring. Prime candidates for fall division include bearded iris, daffodils, grape hyacinths, sweet violets, thrift, Louisiana phlox, candytuft, St. Joseph’s lilies, daylilies, Shasta daisies, purple coneflowers, gloriosa daisies, mallows and others. Prime time to do all of this is late September and especially October.

Remodel the landscape

Our landscapes have taken some real body blows the past couple of years. Extreme cold, heat and drought have left us with gaps and damaged plants where good designs formerly grew. Fall is the ideal time for replacing them. Nurseries are well stocked and designers have more time now than they will in the spring. Plants set out now will have eight months to establish new roots before summer’s hot weather rolls back into town. Start with a plan and work to fulfil it. You’ll be pleased with the results.

Spring bulb plantings

Success with tulips, daffodils and other spring bloomers isn’t as easy as just buying bulbs and sticking them into the ground. You need to choose varieties carefully and plant them according to directions meant for this part of America. Tulips must be “pre-chilled,” meaning they must be put into the refrigerator for at least 45 days at 45 degrees to simulate the effects of a northern winter. Our winters here aren’t cold enough to foster normal stem growth and blooming. Without the prior pre-chilling the bulbs will produce flowers on very short stalks, often only 2 or 3 inches tall. Plant the pre-chilled bulbs into your garden the last part of December, once soils are finally cold. The same applies to Dutch hyacinths.

Daffodils and narcissus, by comparison, can be planted as soon as you buy them, but you need to choose your varieties carefully if you expect them to come back and repeat their blooming in successive years. While most tulips only bloom their first year, early-flowering and small-blooming narcissus, jonquils and daffodils have the best chance of establishing and multiplying. Varieties like Carlton and Ice Follies are great repeat bloomers, while King Alfred, Unsurpassable and Mount Hood usually only bloom their first year. Grape hyacinths are also good repeat bloomers.

Prepare for first frost

As improbable as it seems, the first killing frost of the season may only be six or seven weeks away. Wise gardeners will have frost cloth bought and on hand, perhaps even pre-cut and ready to apply over their beds. It can make 6 or 8 degrees’ difference in plant survival from cold.

You can hear Neil Sperry on KLIF 570 AM on Saturday afternoons 1-3 p.m. and on WBAP 820 AM Sunday mornings 8-10 a.m. Join him at www.neilsperry.com and follow him on Facebook.