PERENNIALS FOR TEXAS

Perennials can be colorful and showy like annuals, but they are generally a more permanent plants in the garden, providing beauty for years. Like annuals though, they can be more high-maintenance in the landscape.


Perennial plants live for three years or longer, and do not die after flowering and setting seed, like annuals and biennials do.

  • “Perennial” is used as an abbreviation for “hardy, herbaceous perennial”—group of non-woody, hardy plants grown for attractive flowers and foliage.

  • Some perennials will go dormant and disappear from the garden during winter, while others will be evergreen.

  • Successful perennials in Texas must be able to withstand summer heat, humidity, rain/lack of rain, and diseases that may occur. Do not plant perennials recommended in books for other parts of the country that wont thrive in the Texas climate.

PLANNING THE PERENNIAL GARDEN

Gardening with perennials is interesting, exciting, and fun—especially after you have become more experienced. Learning and careful planning is required for best results when utilizing perennials.

  • Bloom seasons and length of blooms will depend on the variety of perennials. Some will bloom over many seasons while others for just a few weeks.

  • Utilizing perennial varieties that bloom at different times will keep the garden interesting through much of the year.


Important Questions When Planting Perennials

  • What species or cultivars are best fro Texas?

  • How tall will the plants grow?

  • What colors are the flowers?

  • What light conditions does the plant prefer—full or part sun, part shade or shade?

  • Do they need excellent drainage?

  • Are they evergreen?

  • If they go dormant—when?

  • How fast will they spread?

With planning, perennials can be used make the landscape stand out in a variety of ways.

  • Perennials borders or mixed borders (can include annuals, bulbs, shrubs, and small trees)

  • Tucked among pockets of shrubs, brightening the area up when shrubs are not in bloom.

  • Container specimens to add focal points.

PLANTING & TRANSPLANTING

Proper bed preparation is the first step to planting perennials for success:

  1. Remove weeds and other unwanted plants from the garden bed. Weeds and plants may be eliminated with a non-selective weed-control. Wait proper amount of time as listed on weed control if planting.

  2. Till and turn the soil to a depth of at lest 8 to 12 inches.

  3. Spread a 4-inch layer of compost, aged manure, rotted leaves, finely ground pine bark, or sphagnum peat over the bed. If needed, add sand, lime, or sulfur during this stage. Test soil through county extension office if you wish to know more about your soil fertility.

  4. Blend amendments thoroughly into the top 4 to 6 inches, rake smooth, and begin planting.

Perennials are generally planted using transplants or divisions, but seeds can work too with patience.

  • Spring- and early-summer flowering perennials are generally planted October through early December

  • Late summer- or fall-flowering perennials planted from February through April, or in fall.

Perennials can be planted throughout winter when the weather is mild, especially in south Texas.


PLANTING TRANSPLANTS

  1. Space perennial plants as listed on the label, references, or local guides. Most perennials grow much larger than the transplant, so do not crowd them.

  2. Plant transplants, keeping the top of the rootball slightly above or even with the soil. Many perennials rot if planted too deeply. Tightly packed roots should be separated before planting. Place a slow-release granular fertilizer in the planting hole. Firm soil around the plant once finished planting.

  3. Water in new transplant according to needs. Root stimulator may be applied according to label.

  4. Mulch bed 3 to 4 inches deep to help control weeds.

Some perennials can be easily grown from seed. Generally planted directly into garden beds or outdoor containers. Plant after frost or freeze danger and enough time to establish before winter—April through August.


CARING FOR PERENNIALS

Perennial garden beds require fertilizing, watering, grooming, staking, dividing, cutting back, transplanting, weeding, and mulching. It’s best not to plant more perennial than time allows for.


WATERING

Watering is essential to the success of newly planted perennials, especially during dry, hot summer weather. Water plants deeply and slow over a period of time for best absorption. Sprinklers can be used, but they may damage flowers and promote leaf diseases. Soaker or Drip hoses are best for garden beds. Mulch layered 3 to 4 inches thick conserve moisture and reduce irrigation in perennial beds.


FERTILIZATION

Before planting, apply a small amount of granular fertilizing to the planting hole. Follow label directions. During the growing season, established perennials can be fertilized in March or early April and again in early Fall. A light fertilizer application may be made in Mid- to late Spring to provide a boost through the summer, but don’t overdo this application though. It can be best to use an organic fertilizer in mid- to late spring to prevent burning. Spread fertilizer granules throughout the garden bed every, being sure to water into the soil well, and washing the granulx ecces off the plant foliage to prevent leaf damage. Use high-quality granular fertilizer that is for roses or multi-purpose with a 3:2:1 ratio (including 15-5-10, 21-7-14 and 18-6-12). It is best not to fertilize when temperatures are above 90 degrees Fahrenheit, which can cause excess stress on a plant.


PEST CONTROL

Pest control may be needed with perennial gardening. Planting tough, well-adapted perennial plants will reduce pest problems.

Make sure to read pest control aid directions before use.

  • Caterpillars will damage plants by chewing holes in leaves.

  • Whiteflies are more difficult insects to control, more-so in mid- to late- summer when populations are at their peak. Adults are small, snow-white flies; larvae appear as small disks under leaves.

  • Aphids group on flower buds and new growth, sucking sap from the plant. Fairly easy to control may return, requiring additional pest control applications.

  • Sucking insets such as leaf hoppers, thrips, and plant bugs cause small white specks that appear on foliage of perennials—damage is generally cosmetic, but extensive damage can weaken the plant.

  • Spider Mites can devastate plants, mostly during hot, dry weather.

  • Slugs and Snails will feed on hostas and other succulent-leaved plants in shady areas. Use baits to control according to label directions.

Perennials that are well-adapted and planted in the correct locations generally have little disease problems. Leaf spots caused by powdery milden and fungi will occur sometimes and can be treated with fungus control aids. Crown and root rot can occur with improper drainage, when it rains excessively, or when a plant is not well-adapted to the Texas climate.


PERENNIAL QUICK LISTS


SUN-TOLERANT PERENNIALS

  • Amaryllis, Hardy

  • Artemisia, Powis Castle

  • Canna

  • Chyrsanthemum

  • Daylily

  • Fall Aster

  • Gloriosa Daisy

  • Grasses, Ornamental

  • Hibiscus (mallows)

  • Iris

  • Pinks

  • Purple Coneflower

  • Purple Heart

  • Red Yucca

  • Rock Rose

  • Salvias

  • Sedums

  • Shasta Daisy

  • Thrift

  • Yarrow


SHADE-TOLERANT PERENNIALS

  • Columbine

  • Fern, Autumn

  • Fern, Japanese Holly

  • Fern, Southern Wood

  • Four O’clocks

  • Gingers

  • Hellebores

  • Hostas

  • Leopard Plant

  • Oxalis

  • Oxblood Lily

  • Resurrection Lily

  • Sprider Lily

  • Summer Phlox

  • Summer Snowflake

  • Spiderwort

  • Sweet Violet

  • Umbrella Plant (paper plant)


BEST FOLIAGE PERENNIALS

  • Artemisia, Powis Castle

  • Elephant Ears

  • Fern, Autumn

  • Fern, Japanese Holly

  • Fern, Southern Wood

  • Grass, Dwarf Fountain

  • Grass, Maiden

  • Grass, Mexican Feather

  • Grass, Gulf Muhly

  • Hostas

  • Lamb’s Ear

  • Leopard Plant

  • Purple Heart

  • Umbrella Plant (paper plant)


PERENNIAL EXPANDED LIST

  • Agapanthus

  • Anisacanthus

  • Bee Balm

  • Black-Eyed Susan, Perennial

  • Daisies

  • Blue Plumbago

  • Bouncing Bet

  • Butterfly Weed

  • Blazing Star

  • Candytuft

  • Canna

  • Catmint

  • Chrysanthemum

  • Firecracker / Cigar Plant

  • Columbine

  • Coneflowers

  • Coreposis

  • Daylilies

  • Dusty Miller

  • Echinacea; Conflower

  • Fall Aster

  • Four O’clocks

  • Gaillardia

  • Garden Mum

  • Gaura

  • Gayfeather

  • Gingers

  • Goldenrod

  • Gregg’s Mist Flower

  • Hellebores, Lenten Rose

  • Hibiscus, Hardy

  • Hosta

  • Hypericum; St. John’s Wort

  • Iris, Bearded

  • Iris, Lousiana

  • Jerusalem Sage

  • Lavender

  • Liigularia

  • Mexican Mint Marigold

  • Mexican Oregano

  • Mexican Petunia

  • Mexican Tarragon

  • Obedient Plant

  • Primrose

  • Pincushion Flower

  • Red-Hot Poker

  • Rock Rose

  • Penstemon

  • Phlox, Louisiana

  • Phlox, Summer

  • Pincushion Flowers

  • Dianthus; Pinks

  • Pride-of-Barbados, Red Bird of Paradise

  • Purple Coneflower

  • Purple Loosestrife

  • Red Hot Poker

  • Red Yucca

  • Russian Sage

  • Salvia, Anise

  • Salvia, Autumn Sage

  • Salvia, Henry and Augusta Duelberg

  • Salvia, Indigo Spires

  • Salvia, Mexican Bush

  • Showy Stonecrop

  • Sedum

  • Shasta Daisy

  • Skullcap

  • Sweedwell

  • Spiderwort

  • Southernwood / Artemisia

  • Sundrop

  • Thrift

  • Turk’s Cap

  • Verbena, Perennial

  • Veronica

  • Violet, Sweet

  • Yarrow

  • Zexmenia