Learn About Wisterias
How to Sow
Wisteria: Potted Plant Perennial
How to Plant
Planting Potted Plants:
- Choose a location in full sun with loose, well-drained organic soil. Wisteria is a vigorous vine and needs a support on which to grow. The support should be heavy duty as the vine can be heavy. This should be in place before planting.
- Prepare the bed by turning the soil under to a depth of 6-12 inches removing any debris, and lightly raking as level as possible.
- The addition of organic matter (leaf mold, compost, well-rotted manure) benefits all gardens and is essential in recently constructed neighborhoods.
- Plant on a cloudy day or in late afternoon to reduce transplant shock.
- Dig a hole for each plant large enough to amply accommodate the root ball.
- Unpot the plant and gently loosen the root ball with your hands to encourage good root growth.
- Place the top of the root ball even with the level of the surrounding soil. Fill with soil to the top of the root ball. Press soil down firmly with your hand.
- Use the plant tag as a location marker.
- Thoroughly water and apply a light mulch layer on top of the soil (1-2 inches) to conserve water and reduce weeds.
How to Grow
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their germination.
- Mulches also help retain soil moisture and maintain even soil temperatures. For perennials, an organic mulch of aged bark or shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
- Careful watering is essential in getting perennials off to a good start. Water thoroughly at least once a week to help new roots grow down deeply. Soil should be damp at about 1 inch below the soil surface. You can check this by sticking your finger in the soil. Water early in the morning to give all leaves enough time to dry. One inch of rain or watering per week is recommended for most perennial plants. You can check to see if you need to add water by using a rain gauge.
- Until plants become established, some protection from extreme winds and direct, hot sunlight may be necessary. Good air movement is also important.
- After new growth appears, a light fertilizer may be applied. Keep granular fertilizers away from the plant crown and foliage to avoid burn injury. Use low rates of a slow release fertilizer, as higher rates may encourage root rots.
- Wisteria requires regular pruning to keep growth and size under control. Pruning also improves flowering. Prune twice a year-July/August and February. Cut back the current year’s growth to five or six leaves after flowering in July or August. In January or February, cut back the same growths to 2 or 3 buds to ensure that the flowers will not be hidden by the leaves. Wisteria blooms on old wood so be careful to not prune off all the flower buds. The idea is to prune the long branches back after it blooms to keep the vine under control and the flowers visible next spring.
- Provide extra water from July to September to help with bud development for next year’s flower display.
- Seedpods may be left on the plant for winter interest. Caution, however, that if you want to use them in arrangements if you bring them indoors they may explode in the warm temperatures.
Common Pests and Problems
Common Disease Problems
Bacterial Leaf Spot: First signs are small translucent spots with a broad yellowish edge that slowly enlarge and become angular or irregularly circular with a reddish center. It thrives in cooler temperatures. The disease may also affect and disfigure flower heads. Burpee Recommends: Avoid overhead watering. Do not work around plants when they are wet.
Botrytis: This fungus causes a grey mold on flowers, leaves, stems and buds. It thrives in cool wet weather conditions. Burpee Recommends: Avoid watering at night and getting water on the plant when watering. Make sure plants have good air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Cercospora Leaf Blight: Small flecks which develop a yellowish halo appear on the leaves and turn brown and coalesce. They cause the leaves to wither and die. Burpee Recommends: Contact your Cooperative Extension Service for fungicide recommendations.
Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.
Root Rots: A number of pathogens cause root rots of seedlings as well as mature roots. Burpee Recommends: Make sure your soil has excellent drainage.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Japanese Beetles: Burpee Recommends: Hand pick early in the morning into a bucket of soapy water.
Leafminers: These insects bore just under the leaf surface causing irregular serpentine lines. The larvae are yellow cylindrical maggots and the adults are small black and yellow flies. They do not usually kill plants, but disfigure the foliage. Burpee Recommends: Remove affected foliage. Sanitation is important so be sure to remove all debris at the end of the season.
Scale: Small bugs look like brown, black, gray to white bumps on the stems of plants. Scale may not have any apparent legs and may not move. Scales have a sucking mouth part. Scale may produce honeydew so leaves and stems may be sticky. Scale can weaken the plant causing it to grow very slowly and may wilt at the middle of the day. Burpee Recommends: Completely spray the stems with insecticidal soap. For a severe infestation contact your local County Extension Service for recommendation for your area.
Vine Weevil: This insect cuts irregular notches in leaf margins and grubs feed on plant roots, sometimes causing the death of the plant. Adults are approximately 5/16 inch long, dull black with dirty yellow marking on the wing cases. The grubs are c-shaped, 3/8 inches long, with light brown heads. Burpee Recommends: Handpick adults at night, shake the plants over newspaper to dislodge them. Check under pots where they hide during the day. Check with your Cooperative Extension Service for pesticide recommendations.
Can I grow wisteria in a container? No, it will be a vigorous vine and needs plenty of room to grow.
Do I need to prune my wisteria? If your wisteria has plenty of room to grow you can leave it unpruned, but blooming is improved when plants are pruned, and it is easier to see the flowers as well. Also, regular pruning keeps the plant a controllable size.
Why hasn’t my wisteria bloomed? There are a number of possible reasons wisteria may not bloom. Wisteria needs at least 6-8 hours of sun per day. Wisterias also may not bloom for several years after they are planted as they mature. Late frosts and high winds may also damage flower buds. A fertilizer with too much nitrogen may cause green growth at the expense of flowers.
Does wisteria attract pollinators? Absolutely! It is a bee, butterfly and hummingbird magnet.