Geranium: Bare Root or Potted Plant Perennial
How to Plant
Perennial geraniums are available as bare root or potted plants.
Planting Potted Plants in the Garden:
- Select a location in full sun or part shade with good rich moist organic soil.
- 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.
Planting Bare Root Plants in the Garden:
- Select a location in full sun with good rich moist organic soil.
- Dig a hole deep and wide enough to accommodate the bare root.
- Set the plant so that the crown is at or just slightly below the ground level. Allow the roots to fan out from the crown at around a 45 degree angle. Roots should spread out separately, like stretched fingers, from the crown, and not bunch up. It may be helpful to build a cone-shaped mound of soil in the bottom of the hole and spread the roots around it. It is very important to set the roots such that the crown is roughly level with the ground.
- Cover the roots with soil and tamp down firmly to get rid of air pockets. Fill the soil to just the top of the crown, where the top growth and leaves will emerge. Make sure all the roots under the crown are in good contact with the soil.
- Water very well to fully saturate the roots and the soil.
- Wait until new growth starts to appear before applying a layer of mulch.
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 such as Garden-tone, as higher rates may encourage root rots.
- In colder regions, apply another layer of mulch (1-2 inches) after the ground freezes in fall. Evergreen boughs (from Christmas trees) provide additional protection. Remove this mulch in the spring.
- Divide perennials when plants become overcrowded, bloom size begins to diminish or plants lose their vigor. Geraniums can be divided every 2-4 years in spring or fall four weeks before the ground freezes. Geraniums have spreading roots. Spreading root systems have many slender matted roots that originate from many locations with no distinct pattern. These can crowd out their own centers. They can usually can be pulled apart by hand, or cut apart with shears or knife. Replant one division where the plant was originally and plant the extra divisions elsewhere in your garden or give them away to gardening friends. Plant the divisions immediately, or as soon as possible, and water well.
- Many gardeners do not cut back perennial flower seed heads in the fall, but wait until early spring before the new foliage appears. This provides food for wildlife over the winter.
- Geraniums make a great groundcover in the woodland garden. They are also great for rock gardens.
Common Disease Problems
Botrytis: This fungus causes a grey mold on flowers, leaves, stems and buds. It thrives in cool wet weather conditions. Burpee Recommends: Remove affected plant parts, 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: Remove infected plants and destroy all plant debris.
Cucumber Mosaic Virus: This virus causes yellow mottling on foliage, distorted leaves that curl downwards, and stunted growth. White streaks may also appear on flowers. It is spread by aphids, garden tools and gardener’s hands. Burpee Recommends: There is no cure for this disease. Remove and destroy infected plants. Control aphids which spread the disease. Be careful when working in the garden and do not touch any plant until you have washed your hands or gloves after touching infected plants. Clean tools after working with each plant.
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.
Rust, Brown: Dark brown masses of spores form in pustules on both leaf surfaces. Burpee Recommends: Remove infected leaves and discard into the trash.
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.
Geranium Sawfly: The larvae of this insect are greenish grey caterpillars with black heads that live on the undersides of leaves where they make rounded holes. The adult is a black fly. Burpee Recommends: Check with your Cooperative Extension Service for pesticide recommendations.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
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.
Whitefly: These are small white flying insects that often rise up in a cloud when plants are disturbed or brushed against. Burpee Recommends: They are difficult to control without chemicals. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for pesticide recommendations.
What’s the difference between annual and perennial geraniums? The genus Geranium refers to a hardy perennial plant that has a mounded, spreading habit with lobed foliage and small flowers in shades of blue, pink and white. What we call annual geraniums are a different genus, Pelargonium, and they are not hardy and have showy flower clusters, or scented leaves. See Geranium listed with annual plants for more information.
Are geraniums fragrant? No.
Can geraniums be used for cut flowers? No. Typically geraniums are more used as ground covers.
Do geraniums attract pollinators? Yes, geraniums attract butterflies.
Are geraniums deer resistant? Yes they do tend to be deer resistant.