Hydrangea Help

Hi.

Can anybody help me with this. My Hydrangea did not flower as well as normal last summer and started showing signs of the picture. It has got a lot worse as the picture is from a couple of weeks ago. I was wondering what the best solution is to get it back to what it was.

For the past month i have been watering it every night with the currant dry spell we are having. I am located in the north west of England and my garden is east facing.

 

Hi @ianbamber ,

Do the brown bits of the leaves feel crispy?

To me it looks like one of two things ( or a combination of both ) .

One is getting scorched by the sun.

The other is the watering. You say you're watering it every night..... it's best to give it a good soak and then leave it for about a week. Hydrangeas are shrubs with roots that go searching for water, by giving it little and often the roots are staying close to the surface, and therefore it is drying out in between watering.

 

I suspect that your current weather this year has not helped. I suspect that the plant broke dormancy early and then temperatures "crashed". Reviewing the day's low for April and May, there have been days when the evening lows got very cold... as recent as May 12 and May 14. If your plant broke dormancy early this year, the sap started flowing and freeze or frost on the 12th/14th could have made the sap expand and freeze, causing injury to the veins and zapping parts of the leaves or all parts of a leaf. Afterwards, the leaves (all of the leaf or parts of the leaf) turn reddish, purplish, brownish, even dark green (almost black).

Once the plant breaks dormancy too early, all you can do is be vigilant of freezes/frosts, keep it well mulched, water it deeply the night before bad weather and protect it. You can use some form of frost cloth to protect it or completely cover it with mulch (in the case of small mophead hydrangeas). When they are big hydrangeas then you have to winter protect them. The critical area to protect in mopheads is the ends of the stems because they contain the invisible flower buds as well as the leaf buds.

Once the damage to leaves, leaf buds or flower buds is done, wait for the plant to recover:
* it will develop new foliage in 2-4 weeks. Old leaves may look ugly until then.
* if stems are also damaged, they may take 3-4 weeks to develop new ones. The old ones can be pruned to the ground but if you are not sure they are dead, you can always (a) carefully scratch the stem with your nails to see if you see green or (b) cut the stem from the top downwards in 3-5cms increments and stop if you see green or get to the bottom.
* Flower buds will be invisible until they open. When they open, they resemble little broccoli heads that grow in size until they begin to form the mophead or lacecap blooms. If the flower buds got zapped, the broccoli heads may be partly brown or completely brown depending on the amount of damage.
* keep the soil as evenly moist as you can and delay fertilizing until after the plant recovers and there is no more chance of frost.

Watering nightly may be too much unless you have soil that drains too well, like sandy soil. This can promote root rot. Is your soil too wet or soggy? Pinch some soil in between two fingers; if you see water droplets, you may be watering too much or the soil is not draining well.

To tell if you need to water, insert a finger into the soil to a depth of 10cms and water if the soil feels dry or almost dry. Hydrangea roots grow like a pancake to a depth of about 10cms so keeping those 10 cms moist is important.

To tell if you watered enough, water whatever amount of water you normally use. After a while, insert a finger into the soil to a depth of 20cms and see if the soil feels wet, moist or dry. If the soil feels dry then increase the amount of water. Always water the soil and never the leaves. Start watering near the crown, where the stems originate from, and go outwards in all directions.

Hydrangeas begin to suffer from heat stress once temperatures get to around 29C or higher. When this happens almost every day, consider increasing the amount of water from Spring watering levels to Summer watering levels. In the Fall, reverse this process and decrease the amount of water from Summer watering levels back to Spring watering levels. When the plant goes dormant and the leaves turn brown then water once a week or once every two weeks depending on local rains. If winter is dry, consider watering if a finger inserted into the soil to a depth of 10cms feels dry. It is hard to tell if they need water in winter if all the leaves have browned out. They need some but not as much as in the Spring when the plant is in "grow mode". Only the roots are usually doing any much growing during winter. Once you see leaf out in Spring, consider restarting watering at Spring levels.