Winters in Texas are fairly mild, with temperatures that seldom dip down to subzero levels. Even in North Texas, which experiences the state’s coldest conditions, temperatures generally fluctuate between 30 – 50˚F (-1 to 10˚C). There may be a couple of inches of snowfall each year, and nights may be significantly cooler than days. In the southern part of the state, winter temperatures tend to range from 60 – 70˚F (16 – 21˚C). Cold waves may occasionally occur, but these are rarely prolonged.
Though Texas is not known for having winter conditions that damage tough evergreen plants, it pays to be prepared. During years with unpredictable temperatures, frosts can severely damage tender perennials that may have otherwise been saved had they been cut down, mulched, or brought indoors. Of course, the best ways to prepare for the cold would differ from one region to another. Texas has five gardening zones; some winter-flowering plants may be more likely to flourish in one zone vs another.
Gardening Zone I (Northwest), which is classified under USDA hardiness zone 6, has minimum temperatures of -10 to 0˚F (-23 to -18˚C). Gardening Zone 5 (South), classified under USDA zone 9b, has temperatures that stay above 25˚F (-4˚C) all winter. Some flowering plants listed below may bloom as far north as Gardening Zone I if they are protected from frost and snow. Low-maintenance and cold-tolerant, they should be brimming with life all winter.
1) Cyclamen (Cyclamen spp.)
Many a florist’s favorite cold-weather shade plant, cyclamen produces remarkably vivid blooms that last for several weeks to months. It belongs to a group of plants under the Primulaceae or primrose family, which tends to thrive in alpine regions. This perennial stakes its place and can spread via tubers, from which its rosette of graceful, heart-shaped leaves and emergent floral stalks arise. It’s a no-nonsense addition to the winter garden as it can tolerate temperatures that dip down to -4˚F (-20˚C).
One exceptionally frost-hardy species, ivy-leaved cyclamen (C. hederifolium), can reportedly survive outdoor frosts and temperatures down to around -22˚F (-30˚C)! The most common cultivars, however, are usually hybrids of C. persicum. These should withstand the outdoor winter temperatures of southern Texan regions with well-draining soils. In North Texas, it may be prudent to overwinter these plants indoors. Note that, as soon as temperatures rise to above 20˚C (68˚F) in spring, these plants will naturally enter a period of dormancy.
2) Winter pansies (Viola spp.)
Some of the most ubiquitous flowering plants in regions with mild winters, many members of the Violaceae family have a knack for thriving in cool temperatures. In the wild, some of these perennials repeatedly prove that they are tough enough to withstand mild frost and snow exposure in outdoor flowerbeds. Due to their petite size and their spritely appearance, violas are some of the most charming additions to window containers and hanging baskets.
Some of the best Viola cultivars for winter cultivation in Texas are those belonging to the ‘Sorbet’ series. These plants produce flowers with an incredible range of vibrant colors, from deep purple to the brightest lemon yellow. To accentuate their diversity of winter hues, it’s best to plant several cultivars side by side. When exposed to full sun and moist substrates, their shoots should maintain a compact structure measuring just 6 inches (15 cm) tall at the peak of their growth.
3) Petunias (Petunia spp.)
The mild winter climate of southern Texas is perfect for the delicate yet perky blooms of petunias. Those that are frequently cultivated in home gardens are cultivars belonging to the nothospecies, Petunia x atkinsiana. These plants are complex, large-flowered hybrids between P. axillaris, P. integrifolia, and occasionally, P. inflata. They are winter-hardy in zones where temperatures do not drop to below 35˚F (1.7˚C). In regions with cooler winter temperatures, they are best grown as spring or summer annuals instead.
As petunias are not frost-hardy, they may struggle to flower and persist through the fluctuating temperatures of North Texas. In the state’s upper zones, they may be overwintered indoors, by a particularly sunny window or in a greenhouse. Intolerant of shade and drying winds, the blooms look best in protected yet sunny areas. Those grown as cool weather annuals should flower until late December. Some cultivars (e.g., ‘Wave’, ‘Laura Bush’) may withstand January temperatures and re-bloom in spring.
4) Snapdragons (Antirrhinum majus)
Snapdragons are often forgotten during winter because many novice gardeners aren’t aware of their remarkable hardiness in mild climates. These stunning plants are hardy to USDA zones 7 – 10, where they can be grown as annuals. They often flower deep into fall and winter if they are provided with protection and ample moisture. In the central to southern regions of Texas, they should withstand nighttime temperatures down to 40˚F (4˚C).
Well-acclimated stands of this species may even tolerate sub-freezing temperatures but do note that these will likely impact their ability to bud as well as the longevity of their flowers. A good way to test which cultivars are best suited to your area would be to grow them alongside one another to create a lush snapdragon bed. You may mix both tall varieties (rockets and sonnets) with dwarf ones (floral showers, bells), placed along the forefront of the landscape bed, for a superb show of rainbow floral spikes.
5) Winter honeysuckle (Lonicera fragrantissima)
Also known as fragrant honeysuckle and “sweet-breath-of-spring”, the winter honeysuckle should enliven the Texan garden in late winter. Hardy to USDA zones 4 – 8, this multi-stemmed perennial maintains a bushy and leafy appearance through mild winters. Its cool-season blooms arise along the nodes of stems, usually just before their new leaves begin to grow. Fragrant and cream-colored, they serve as a fantastic source of nectar for honey bees that are active from December to March.
Fairly straightforward to cultivate, the winter honeysuckle thrives under direct sun and when rooted in well-draining soil. Its generous tufts of blooms arise on older stems, so regular pruning should help maintain a compact shrub without compromising its winter interest. Some gardeners opt to cut down long stems, particularly those jutting outward from hedge plantings. This is done after the flowering period to encourage the growth of new stems that should mature over the course of spring to fall – just in time for winter.
6) Winter jasmine (Jasminum nudiflorum)
Another oriental shrub with a penchant for flowering in cool temperatures, the winter jasmine can send out its simple yet incredibly fragrant blooms from November to March. In the southern states of the US, it is more likely to bloom in late winter (January to February) or early spring. In warmer, frost-free zones, the flowering period may begin earlier in winter. The right time to outplant this species to ensure that it can survive the coming winter is around 2 – 3 weeks after the final frost of spring.
Hardy to USDA zones 6 – 10, winter jasmine can tolerate temperatures down to -5˚C (23˚F) as long as it is protected from frost. If you live in one of the northern regions of Texas, where unpredictable frosts may occur late in spring or early in fall, you might consider placing your winter jasmine in pots for easy re-location. In regions with warm winters, this species may be rooted directly into the ground and cultivated as a hedge.
7) Christmas rose (Helleborus niger)
The versatile Christmas rose is known for two things – for flowering during the coolest time of year and for containing a potent cocktail of toxins. This member of the Ranunculaceae family is an evergreen winter-bloomer. Hardy to USDA zones 3 – 8, its well-established stands can tolerate temperatures down to -10˚C (14˚F). In the mild to moderate winters of Texas, its leaves should remain on their stems and should continue to support the growth of the plant.
To produce a profusion of winter flowers, your Christmas rose should be placed in a partly shaded or protected area. Those grown along the base of large shrubs or around the trunks of tough trees should glisten with blooms from late December to March. A closer look at the blooms reveals elegant, pure white sepals surrounding a tuft of bright yellow stamens. As the entire plant is toxic, make sure it is not easily accessed by unsupervised pets or children.
8) Primroses (Primula spp.)
Though the primrose is typically perceived as an early-spring bloomer, it can be forced to produce its vibrant flowers in winter. Typically sold as an annual potted plant for indoor or porch locations, this charming perennial grows to just 12 inches (30 cm) tall in optimal environments. In zones with mild winters, its wrinkled, bright green foliage maintains an evergreen habit. These are usually arranged in a rosette formation around a dense tuft of seemingly energetic floral stalks.
In the mild winters of southern Texas, primroses may survive in flower beds or window containers provided they receive some protection from harsh winds and snow. The best types for zones with cooler winters include Allioni’s primrose (P. allionii), silver-edged primrose (P. marginata), and Siebold’s primrose (P. sieboldii).
The most common cultivars sold in plant nurseries are usually grouped under Primula acaulis. Depending on ambient temperatures and photoperiod, their well-established stands may readily bloom in late winter. Note that, while these can tolerate cool temperatures, they are unlikely to survive through hot summers.
9) Sweet alyssum (Lobularia maritima)
An eye-catching member of the Brassicaceae or crucifer family, sweet alyssum can bring phenomenal charm to a coastal winter garden. Typically found in calcareous habitats situated up to 300 meters above sea level, its wild stands are no stranger to salty winds and alkaline conditions. A low-maintenance perennial (often grown as an annual), it is cultivated as a seasonal ground cover plant in early spring. In Texas, however, the mild fall and winter temperatures may support its continued growth through the coolest time of year. Flowers are likely to appear as early as late winter.
Arising in clusters of the most delicate white or pastel-shaded hues, sweet alyssum blooms are a common feature in North Texan gardens. Hardy to USDA zones 5 – 9, this species may need to be overwintered in your home or greenhouse if there is a risk of frost. As its low-maintenance mounds can spill over the edges of pots and baskets, it can be used to complement other indoor winter flowers.
10) Rainbow pink dianthus (Dianthus chinensis)
Also known as “Sweet William” and “Carnation”, dianthus is a fantastic flowering plant for the moderate winters of northern Texas. Its acclimatized stands, which are usually cultivated and sold as annuals, can bloom from November to April. These may tolerate light frosts if they are protected from winds.
In USDA zones 5 – 9, however, dianthus may persist as a perennial for a short time. Regardless, most gardeners prefer to cultivate this plant, from seed, as annuals because it grows quickly and flowers as soon as its stems have matured. Try to situate them in pots or moveable containers so that they can be moved beneath an eave or into a greenhouse when temperatures are expected to drop to below 50˚F (10˚C).
Cropping up in the forests and grasslands of some of East Asia’s temperate zones, this charming ornamental boasts blooms with complex patterns and a spectrum of pink, white, red, and black tones. Its soft petals have serrated outer margins, giving them a somewhat quirky and paper-like appearance. In Texas, this cool-season plant may grow dormant as soon as warm temperatures set in.
