How to look after Forsythia?

Forsythia are considered hardy and easy-to-grow shrubs. They tolerate a wide range of soil types, and grow best in full sun and light shade. Because of their vibrancy and delicate flowers, Forsythia are a great choice for a flowering hedge. Adding a brilliant pop of colour to your garden. Plus, they’re easy to share! You can take cuttings of Forsythia to propagate another, and you can also cut the flowers off, to use as decoration.

Whilst they are straightforward shrubs, Forsythias do require some pruning. Because, without it, they tend to develop into tall, clumsy shrubs with congested growth and bare base stems.

However, when and how you go about pruning depends on what kind of Forsythia you’re looking after. Bear in mind, though, that pruning of any Forsythia should be complete before mid-July, if you want to give the plant enough time to put on new growth and develop flower buds.

Food and water

If your Forsythia is new, it will need regular watering for the first few years. Particularly during dry spells in spring and summer.

Then, once their roots are established, they should be relatively drought tolerant and cope well without additional watering. Plus, Forsythia let you know they’re thirsty when their leaves begin to shrivel.

Generally, Forsythias need little to no regular feeding in most soil types. However, feeding is important if you want to encourage new growth after pruning in spring.

Also, Forsythias can produce odd-looking, flattened, elongated shoots that look like a bunch of squashed stems. These are called ‘fascinations’.  And although they look a bit strange, they’re not actually harmful to the plant.

Pruning young Forsythia plants

For young forsythia, you can basically let them get on with things themselves. If pruning is required, make sure it’s done in spring, immediately after flowering.

Make sure you:

• Simply remove any dead, damaged, or badly positioned shoots after flowering in late spring.
• And as an interesting (bit grim) aside, young forsythia can be fed twice a year with blood, fish, and bone to help establish a good root system!

Pruning established Forsythias

Established Forsythias should be pruned in mid-spring, immediately after flowering. And be aware that pruning any later means that the following spring’s flowering might be a little lacklustre.

Make sure you:

• Cut back flowered growth to vigorous upward and outward-facing shoots lower down.
• Remove up to 1/5 of the old stems from the base. This is important because it encourages new shoots to sprout.
• Then, thin out any crowded shoots in the centre of the bush, and remove any weak growth.

Pruning neglected forsythia

Give your misshapen or badly congested forsythia a new lease of life by hard pruning. This is best done between autumn and early spring. But bear in mind, the plant won’t flower the first post-prune spring.

The process is the same for Forsythia hedges, which should be pruned annually.

Make sure you:

• Cut out the thickest, oldest stems from the base.
• Remove the oldest wood, up to a third of the stems – each winter. And cut back any crossing branches.
• Then reduce the remaining wood by half after flowering.

Pruning wall-trained Forsythia

For wall-trained Forsythia, the aim is to cover a particular space, and train to horizontal wires or trellis attached to a wall or fence.

Make sure you:

• Reduce the length of flowered stems to one or two buds from the branched that form the main framework.
• If older framework branches haven’t formed well, then cut them out and select younger shoots as replacements.
• Then, tie these new stems into your desired position, to fill any gaps or extend the area covered.