Your perennials have been selected and you’ve got them snug in the ground, ready to show off. Now you need to know how to properly care for them. Let the following suggestions be a guide:

Aster oblongifolius

This aster could be divided and shared with family, friends or neighbors.

Photo Credit: Felder Rushing


Even ‘Miss Manners’ obedient plant can be aggressive and need division.

Photo Credit: Grandiflora™

Phlox paniculata 'Nicky'

Heavy-feeding garden phlox benefit from fertilization.

Photo Credit: Grandiflora™

Water your planted perennials regularly until they’re well-established. Encourage roots to grow deep in the soil by watering for longer periods at a time, fewer times per week. Mulch around the plants to conserve soil moisture, but don’t pile it up around the plant’s stems like a volcano. A donut of mulch around the plant – and about 2 inches deep throughout your beds – is best.

Perennials won’t need frequent fertilization if they’re planted in a well-prepared bed with average or better soil. Fertilizing too much can lead to soft, leggy growth – and you don’t want to encourage lots of growth near the end of the season either. (The new shoots will get nipped in the crisp autumn air.)

Your plants will let you know what they need. If your perennials appear stunted, exhibit chlorosis or show lack of vigor, then you need to fertilize. Heavy feeders like garden phlox or perennials that have been growing in a bed for many years will also need some fertilization. One method is to apply a topdressing of compost or a light application of an organic or chemical general-purpose fertilizer (10-10-10, 12-12-12 or 5-10-5) in spring. Follow directions on the label! Generally, you’ll sprinkle the fertilizer around the base of the plants and, if the soil is dry, water it in. If you think your perennials need a midseason boost, use a foliar feed with a water-soluble chemical or organic fertilizer.

Grooming and Dividing

In fall, check out your perennials around the garden. If the foliage looks diseased or is unsightly, cut it off. Compost the leaves and stalks that look healthy, and try to remove diseased parts from your garden because they can harbor pests for next year. I like to leave the majority of my perennials through the winter, standing proud and tall and providing food or shelter for wildlife.

Many perennials need to be divided every so often to rejuvenate or bloom at their best. Again, your plants will let you know what they need – just keep your eyes open for the signals. The perennials that die in the middle or don’t seem to produce as many blooms need to be divided. Or sometimes they’ve just outgrown their space, and you need to divide then.

In most cases, when dividing, the plants should be dug out of the garden and cut apart. I use my flat-edged gardening spade to divide my plants, and it does the trick nicely. Don’t worry – most perennials are tougher than you think and will thank you later for splitting them up. When you divide them, you could incorporate some compost into the hole before replanting. Treat the newly divided plants as you would newly planted ones. Water them until they’re well-established again.

Give your perennials plenty of time to re-establish before they come into bloom again. Divide plants that bloom in spring and early summer later in the season, like late summer or early fall. Those that bloom later in the season can be moved or divided in spring.

Keeping a journal about your garden is always helpful, too. When your perennials are popping their heads up in spring, you’ll know which might need dividing this year, which might need moving altogether and which are perfectly fine where they are. You can always add something new or fine-tune your garden design. Share the wealth and give your friends and family some of your plant divisions. These are good pass-along plants, as my buddy Felder Rushing will tell you!