Your Ceanothus is dying due to Frost damage if you see foliage browning in the winter. Ceanothus will die due to root rot if you overwater the plant. Canker disease causes sudden death of the Ceanothus plant.
Ceanothus plant is commonly called California lilac or Buckbrush. These plants are grown for their pretty blue flowers that appear in May and June.
Ceanothus plant is easy to grow. Some people do run into some issues with this plant and they mail me. Instead of answering them all I decided to write this post.
Why is my Ceanothus going brown?
Ceanothus turns brown in color when it is suffering from frost damage or wind burn. Ceanothus will also turn brown when it is overwatered or underwatered.
Ceanothus frost damage
In plants that suffer frost damage, new leaf growth is affected first. The leaves and tender stems wither and turn brown.
The bark of such trees will have cracks. If the damage is minimal the plant will recover soon.
Will Ceanothus recover from frost damage?
Frost damage causes death of the stems in severe cases. The plant will recover if it wasn’t damaged severely. Scratch the bark on the lower-side of the plant.
Do you see any green color under the bark? If yes, the plant will bounce back in no time. If there’s no green color beneath the bark the plant’s as good as dead.
Windburn
Windburn is seen in plants that are exposed to heavy winds. The heavy winds steal away the moisture from the leaves and the soil. Such damage is called leaf scorch.
Windburn results in the brown edges of the leaves. You can cover your tender plants with burlap to prevent windburn.
Why are the leaves on my Ceanothus turning yellow?
Ceanothus plant leaves turn yellow when the plant is overwatered. Underwatering causes Ceanothus leaves to turn yellow too.
Overwatering
Overwatering is the common reason why Ceanothus leaves turn yellow. Overwatered Californian lilacs don’t recover usually. Ceanothus plants wilt due to overwatering.
Ceanothus is used to the climate of California, so make sure you don’t overwater the plant. Their habitat is dry, so excess moisture/humidity may lead to issues.
Root rot
Overwatering causes waterlogged conditions in the soil. Prolonged waterlogged conditions lead to root rot.
Check your Ceanothus’ roots for any damage due to fungal pathogens. Dig on one side of the plant and check the roots, are they mushy? If they are mushy, the plant is suffering from root rot.
Does your soil drain excess water? Make sure the soil has good drainage. If clay comprises a good portion of the soil, Ceanothus is in trouble.
You can add some sand to the soil to make it loose. Ceanothus doesn’t need much watering, so only water when the soil is dry up to 3 inches.
Tip: Ceanothus plants thrive in poor, well-draining soils.
Underwatering
Underwatered Ceanothus’ leaves turn yellow too. This rarely happens as the plant is quite drought-resistant. The plant is used to dry conditions.
Underwatering symptoms are seen in the spring and summer seasons. Underwatered plant’s leaves turn yellow and dry.
Water the plant once a month deeply in the summer. Do not wet the crown of the plant.
Over-fertilizing
Over-fertilizing causes leaves to turn yellow too. Ceanothus grows in poor soils. One should try to provide the same conditions when trying to grow the plant.
Do not even add compost to the soil. You need not try to amend the soil in any way. Ceanothus grows best in poor soils.
Just make sure the soil is well-draining. Don’t even worry about the soil and its richness. Ceanothus is in symbiotic relationship with a nitrogen fixing bacteria.
Ceanothus leaves yellowing and dropping
Ceanothus leaves turn yellow and drop in the spring season as the plant pushes new growth. This is a natural part of their life cycle.
Do not panic when this happens. Some people water their plants or even fertilize them. Don’t do this. If it’s spring, let the plant do its own thing.
Ceanothus not flowering
Ceanothus fails to bloom if the plant has been pruned improperly. Lack of sunlight is another reason why Ceanothus fails to blossom. Too much Nitrogen in the soil is also a reason for blossom failure in Ceanothus.
When it comes to Ceanothus, prune only the finer, smaller branches. Pruning bigger branches doesn’t give the desired results.
Make sure your Ceanothus gets adequate sunlight. Do not let other plants shade your California lilacs.
Too much nitrogen
Did you overfertilize your Ceanothus? Overfeeding your plant has adverse effects. Leaves will turn yellow and the plant fails to absorb essential nutrients.
Overfed plants produce leaves at the expense of flowers. Ceanothus doesn’t require any kind of external supplements.
The plant has its own mechanism to produce surplus Nitrogen. If you provide it via fertilizer, the soil becomes messed up.
Sudden death of Ceanothus
Canker disease causes sudden death of Ceanothus plant. The disease first appears as a round/irregular lesion on the tree.
This lesion is brown colored and if one cuts this lesion dead tissue can be seen clearly. This infections slowly spreads to the rest of the plant.
Cankers infect the parts where mechanical injuries and sunburn happened. So, be cautious around your plants when you prune them.
Prevent Canker on Ceanothus
Try to only plant hardy varieties in your garden. If possible, plant resistant varieties. Prune dead and dying branches as soon as you see them.
Make sure your Ceanothus has good air circulation.
What is eating my Ceanothus?
Leafminers love to eat both the upper and lower leaf surfaces of Ceanothus plant. These tiny, drab grayish moths can be seen hovering around your Ceanothus plants.
Leafminers on Ceanothus
These are moths that love to devour the leaves of Ceanothus plant. The damage won’t be seen in the initial stages of infestation.
Severely infested plant’s leaves turn brown and fall off. The plant will grow back stronger if you keep nurturing it. Cut back the affected leaves when the larvae are still in the mines.
Do Deer eat Ceanothus?
Deers do not eat well-established Ceanothus plants. Deers however can eat newly planted Ceanothus, it happened with one of my neighbors.
Protect your plants with a fence until they get established.
Do Rabbits eat Ceanothus?
As far as I know rabbits do not eat Ceanothus. I am sure many expert gardeners would agree with me.
Happy Gardening 🙂