Plant Care & Growing Guide

Forsythia Care

Forsythias are fairly tolerant of poor garden soil, and they have some drought tolerance once established. Plant them where they’ll get lots of sunlight. Prune regularly to maintain a specific shape and size, or allow these plants to grow wild and embrace the natural look.

Planting

Plant forsythia in full sun and in well-draining soil, four to six feet apart to give them room to expand. Forsythia is perennial in zones 5 through 8.

Plant bushes in the fall when they are dormant. Dig holes twice as large as its root ball, then place it in the hole so the top of the root ball is flush with the ground. Pack the soil around the roots and water.

Light

Forsythia bushes grow best with at least six hours of direct sun on most days. If your plant gets less sun than this, it might not produce as many flowers.

Soil

Forsythias prefer loose, well-draining soil—however, these tough plants show tolerance for clay soil, too. They are not particularly picky about their pH levels and can thrive in both acidic and alkaline soil blends. Good drainage is important, however, so amend compacted soils as needed.

Water

The bushes grow best in moderately moist soil, but they can handle some drought once they’re established. Water new forsythia plants regularly (at least 2 inches of water a week) until they’re established, then only water if you have an extended period with no rainfall.

Temperature and Humidity

Forsythias prefer slightly humid climates. They’re happiest when the temperature is between 55 and 70 degrees Fahrenheit, but they’re fairly hardy in colder temperatures as well. If exposed to prolonged periods of extreme cold, flowering for the following spring may be absent or reduced. Northern gardeners will want to make sure to choose a variety known to have good hardiness in their climate zone.

Fertilizer

Don’t fertilize your forsythia bush until it is about a year old and appears to be in good health. At that point, you can spread approximately a cup of granular fertilizer at the shrub’s base every few weeks throughout the spring and summer.

Types of Forsythia

There are many varietals within the forsythia genus, offering different sizes and shapes. The varieties known as ‘intermedia’ are hybrid plants achieved by crossing weeping forsythia (F. suspensa) and greenstem forsythia (F. viridissima), with traits that are “intermediate” between the two parents. Some of the most common forsythias include:

• Forsythia x intermedia ‘Lynwood Variety’: This varietal boasts larger yellow flowers and leaves that turn an attractive yellow with purple tinges in fall.
• Forsythia x intermedia ‘Meadowlark’: A varietal that grows around 7 to 10 feet tall with a similar spread, it’s known for having very few issues with pests and diseases.
• Forsythia x intermedia ‘Sunrise’: This compact shrub grows to be between 4 and 6 feet tall and wide. Its flower buds are able to withstand colder winter temperatures than many other forsythia varieties.
• Forsythia x intermedia ‘Kolgold’: A shrub that matures at around 4 to 5 feet in height and spread, it sports larger flowers than most forsythia bushes, at roughly 1 inch across.
• Forsythia suspensa: The pure species known as weeping forsythia has pendulous branches that can grow as long as 10 feet, which can be trained up a trellis if you wish.
• Forsythia x intermedia ‘Show Off Starlet’: A dwarf variety with big blooms from base to tip.
• Forsythia koreana: A species variety that blooms earlier than most other Forsythia.
• Forsythia ‘Northern Gold’: Bred for colder climates, this cultivar has reliable blooms and withstands northern winters.

Pruning Forsythia

Prune forsythias if you want to maintain a structured look. Shape them after they have finished blooming in spring. If you wait until July to prune, you run the risk of losing all the flowers for the following spring. If you’re happy with your bush’s shape, you can go for several years without pruning.

Begin by pruning roughly a quarter to a third of the oldest branches, cutting them right down to the ground. This will encourage new growth and a more compact form. You can also selectively cut newer branches to improve upon the overall shape of your forsythia.

Propagating Forsythia

Propagating forsythia plants is the best way to multiply your supply, short of heading to a nursery to get more mature plants. The ideal way to propagate forsythia is through a stem cutting in early to mid-summer, but you can also propagate by layering.

Propagating by Cuttings

1. Using sharp and clean cutting shears, take a 4- to 10-inch long stem from a mature forsythia plant that has flowered for at least a season. Cuttings should be taken after flowering is completing and when the shrub has leaves.
2. Remove the bottom leaves, leaving at least two inches of stem exposed at the bottom.
3. Plant each cutting into a container that’s been filled with a moistened mixture of peat moss, perlite, and sand. Bury the stem cut-side down, with at least one node falling beneath the soil line.
4. Mist the cuttings daily until the roots are about 1 inch in length, which will take at least a month.
5. Once roots have been established, transplant the cuttings into a larger pot placed in a controlled outdoor environment for one or two seasons before planting it in a garden location.

Propagating by Layering

1. Find a long branch on the existing shrub, bend it so that a node touches the ground.
2. Gently scrape away the bark above and below the node.
3. Secure the bent branch with a rock, so it touches the soil, and wait.
4. Roots should form along the layered branch.
5. Cut the branch from the parent shrub, dig up the rooted branch, and plant in a new location.

How to Grow Forsythia From Seed

Not all forsythia bushes will produce seeds, as some are hybrids that are sterile. If you find seeds, be aware that the plants that may grow from them will not be identical to the parents. In addition, propagating forsythia from seeds can take a very long time. Take these steps:

1. Plant a few seeds together, but place groups of seeds 4 to 6 inches apart in a tray or pots filled with potting medium.
2. The seeds should only be sown just below the surface of the soil, no more than a thin 18 of an inch.
3. Place trays or pots in bright, indirect light.
4. Keep the soil moist.
5. When seeds germinate, remove the plastic, and keep soil moist but never soggy.
6. Plant seedlings in the ground or larger pots in the spring after the last frost.

Potting and Repotting Forsythia

Forsythia can grow in pots, and in fact, doing so can contain its aggressive spread. However, you will have to repot the plant every two or three years as it will grow larger. Any material container will do as long as it has drainage holes. Fill it with half rich, well-draining soil and half organic material or compost. Place the pot in full sun and keep the soil moist, but never soggy.

Overwintering

Forsythia bushes do not need any special treatment during the winter because the plants will go dormant. They do not require pruning or watering during winter months, either. If you cut the bush back for the winter, you will lose buds and the bush will likely not flower for at least a season.

Common Pests and Diseases

Forsythias don’t have many pest issues and are deer-resistant. However, these plants struggle with a few diseases.

Forsythia shrubs can be prone to knobby galls forming along the stems, as well as fungal twig blights. Both problems are best treated by removing affected stems. Twig blights can be prevented by keeping the plant well pruned to improve air circulation, and by applying a fungicide.

How to Get Forsythia to Bloom

There are multiple reasons with forsythias may not bloom, including improper pruning, lack of light, and a late winter freeze. Consider the following possibilities:

• Improper pruning: Forsythia set bloom on old wood, so any pruning should be done immediately after blooming in spring. If you wait until late summer or early fall, you run the risk of pruning off next year’s flowers, which will leave you with a rather bare bush for the following season.
• Lack of light: Forsythia bushes need at least six hours of light daily (on average—a few days here or there with less won’t be a huge issue). If you have a few pesky bushes that just aren’t blooming, take some time to observe how much light your plant gets. If you can, trim back nearby trees that may be blocking the light to allow more sun to reach your bush.
• Late winter freeze: A late freeze may damage or destroy the buds before they can open. An exceptionally cold winter can also adversely affect your plant’s bloom period. You may notice only a few flowers blooming low in the shrub where the plant was insulated by a layer of snow.
• Old age: Blooming reduces significantly in old shrubs. You can mitigate this by regularly pruning out old wood to encourage new shoots to grow. Do so by cutting away a third of older canes to make way for newer ones. You can also cut the old canes back to the ground, but you will need to wait at least another season before the plant blooms.

Common Problems With Forsythia

Wilted or Drooping Leaves

Multiple factors lead to wilted or drooping leaves. Plants that haven’t received enough water may droop, and plants that have experienced root rot from too much water will also droop. Lack of light and extreme temperatures are also possible causes.

Curling Leaves

Curling leaves are most likely caused by pests or diseases. Possibilities include aphids, spider mites, leaf spot, and powder mildew. Intense heat may also cause leaves to curl.

Brown Leaf Tips

Brow leaf tips are also likely caused by watering issues, extreme temperatures, or pests and disease. Drought and under watering are particularly likely to cause brown leaf tips in otherwise healthy plants.