Why Is My Forsythia Wilting? (Solved!)

Forsythia bushes, with their bright yellow flowers, are a joyful sight in spring.

One of the earliest splashes of colour in the year, they are common in the UK.

Forsythias are generally hardy, but sometimes they can wilt and fail.

So if you have asked the question “Why Is My Forsythia Wilting?” then read on for answers and solutions.

Forsythias are robust plants, but they may suffer when exposed to drought. Pests like weevil grubs and nematodes can attack the roots and infections such as Twig Blight, Anthracnose Leaf Spot Disease, Verticillium, Monilia and Forsythia Gall Disease can affect growth.

Lack Of Water

This can be a very common occurrence when the weather is very warm and dry.

It can especially affect young or recently transplanted Forsythias.

Leaves look dehydrated, limp and shrivelled.

How to fix:

  • Water the plant as soon as you spot this happening.
  • Ideally water early in the morning but don’t wait for this, if the plant looks like it needs it then water straight away.
  • Water deeply and at the base with a watering can spout, rather than from overhead with the rain head on.
  • The leaves should perk up within a couple of hours.

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Weevil Grubs

Weevils are insects that feed on foliage when adults.

They look like black or brown beetles with a long snout and antennae.

This can result in U shaped scoops being eaten from the leaves of your Forsythia, but this in itself is not too much of a problem as it is easily spotted and does not damage the plant too much.

The real problem is the activity of the Weevil grubs, which feed on plant roots.

They look like white grubs / larvae and overwinter in the soil while eating the root system.

The plant will struggle to take up nutrients and water and will start to noticeably die back.

How to fix:

  • Be vigilant and if you see adult weevils and their feeding pattern on the foliage, it is likely you will have weevil grubs in the soil.
  • If your Forsythia looks weak and stunted then investigate the soil.
  • Remove adult weevils by hand. If weevil larvae are present then remove as many by hand as you can and put both in a container of soapy water to kill them.
  • Also, remove the immediately surrounding soil and dispose (not on the compost heap). Replace with new.
  • Always clean/sterilise plant pots as weevil grubs can hide in these and then get planted out into your garden


Nematodes are tiny worms that can feed on Forsythia and other roots.

They are invisible to the naked eye so can be difficult to identify.

The results are similar to the effects of weevil grubs however, as they eat the roots the plant will begin to visibly deteriorate.

If you see this happen above ground and if the roots are being eaten and weevil grubs are not present – then it is likely nematodes.

Another indication can be the remaining roots looking swollen and knobbly, and foliage that is yellow to brown.

How to fix:

  • Promote well draining soil. Nematodes find it easier to move through water saturated soil, so keeping your soil free draining is a good way to slow them down and decrease their spread. This can be done by introducing grit or sand to your soil.
  • Promote aerated soil. Nematodes do not survive prolonged exposure to the open air so regularly turning the soil will kill those that are exposed.
  • Nematodes don’t like Marigolds, so consider planting these pretty flowers around your Forsythia. Once they have grown and died back, dig the remains through the soil and then plant more.
  • Sterilise tools and pots after use to minimise transfer of nematodes and other diseases.

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Twig Blight and Anthracnose Leaf Spot Disease

Twig Blight fungus affects the branches closest to the ground.

These die back and show internal black fungal growths.

Anthracnose Leaf Spot Disease is a similar fungus to Twig Blight but affecting the foliage instead.

It causes parts of the leaf to die causing round spots or blotches of black, brown or yellow rotting tissue.

Sometimes spores can be seen within the spots.

These fungi are more unsightly than fatal and can usually be resolved with correct management.

How to fix:

  • Keep an eye on your Forsythia and if you see any decomposing twigs, spores or spots on the leaves, act quickly and remove the affected parts.
  • Dispose of any affected material (not in the compost heap).
  • Improve the airflow surrounding your plant by regularly clearing decomposing debris from around the stem.
  • Water gently at the base using the spout of your watering can rather than from overhead using the rain head to minimise splashing and transferring spores.
  • Mulch at the base in spring and late autumn to from a barrier between fallen plant matter containing possible spores.

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This fungus causes deterioration of inner and older parts of the plant.

To investigate, remove a small section of bark from a branch that is deteriorating and if you can see brown streaks running through the bark then this is a way to identify a Verticillium infection.

This can be a difficult fungus to eradicate, it can fatally damage the Forsythia and it can spread to other plants in your garden.

How to fix:

  • You can try removing affected branches if they are few in number.
  • If so, cut them right back to the junction with the main stem.
  • Sterilise shears before and after use.
  • Dispose of all infected material (not in the compost heap).
  • If this does not work and the plant continues to decline and show more infected branches, unfortunately it is time to remove the whole plant and dispose of it safely.


This type of fungus affects may ornamental and fruit trees.

It can cause spoiling of tips during or just after flowering.

Newer branches can also appear discoloured.

How to fix:

  • As Monilia mainly affects new growth you can act quickly and remove the infected tips.
  • There is a good chance your plant will then recover.
  • Sterilise shears before and after using.
  • Cut back about 20cm from the point of visible infection.
  • Dispose of the infected plant matter (not in the compost heap).
  • Promote general plant health by maintaining good airflow through the branches and around the base by regularly clearing any decomposing matter.

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Forsythia Gall Disease

This is usually a bacterial infection but galls can also be caused by some fungi.

It can happen when the stem tissue is damaged in some way, and infection enters.

There will be a formation of knobbly woody growths on the branches.

These grow, merge and eventually can halt growth beyond the gall, causing death to that part of the stem.

How to fix:

  • Avoid accidental damage to stems where possible.
  • You can remove galls by cutting the affected branch 15cm below the gall.
  • When pruning, use sharp sterilised shears and only prune in dry weather.
  • Promote general plant health to minimise infections.
  • Keep the canopy and base clear of debris to maintain good ventilation.

Final Thoughts

Forsythias are very robust plants.

They are often paired next to pink Flowering Currant shrubs.

In most cases issues can be fixed if caught quickly.

If you are having any problems with your Forsythia that have not been covered above, then do drop me a message and I will do my best to help.

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