Hydrangea Issues!!!

Hi,

Thank you for accepting me into this forum.

I wondered if anyone can advise what I need to do with my large Hydrangea I have in my garden... As shown in the first picture the leaves appear to be going purple (almost bruised looking). I then went to the garden centre and was advised that the soil needs feeding due to a possible soil deficiency, since feeding more leaves seem to be wilting and now going brown (pic 2). Can anyone advise what issue this is and how can I stop it?

Thank you.

 

If you have a soil deficiency, I would expect nearby plants to also be affected since hydrangeas are normally not heavy feeders. The only times when I ran into that issue was near the beach where the soil is often sandy and deficient in many nutrients. But, you could also get similar symptoms from a potted hydrangea whose potting soil was nearly depleted of nutrients.


I could not tell if the hydrangea was in a pot or planted in the ground. I assume it is planted in the ground because you said it is a large shrub. A nitrogen deficiency would cause yellowing of hydrangea leaves with a yellow color, not a sandy color. It would also be visible on the whole leaf or most of it. A phosphorus deficiency would make the leaves turn a shade of purple.


Picture 1 seems to show damage from a late frost. Leaves injured by frost tend to turn several colors depending on how well developed they are when the frost strikes. A well developed leaf may turn darker green, almost black, when the frost hits, when sap is flowing and when the frost forms ice crystals that break the leaf veins. You can also see some other leaf colors: purples, reds and oranges in the leaf's injured parts. Damage takes several days to become obvious. The injury in Picture 2 looks like the main vein had an injury, possible due to ice crystals or a root/chemical issue.


Just like leaves can be injured by frost, the stems can be similarly injured and can fail to supply enough water to the leaves. When the leaves lose moisture faster than stems can send moisture from the roots, wilting occurs. The leaves may be eventually die and the stem could also die.


However, wilting per se can also be caused by some forms of environmental stress that might need to be considered and ruled out: too much wind; too little humidity; lack of water or lack of enough water; too much sunlight (they need shade after 10-11am); injury to roots after transplanting; temperatures that typically reach or exceed 29°C.


You can cut off the petiole string that connects damaged leaves to the stem. The plant can produce new leaves in 2-4 weeks, depending on weather conditions. Stems that become dead wood can be pruned all the way down. To avoid future damage, water deeply before a frost, maintain mulch all year around, protect the plant with frost cloth or blankets. Fertilize after chances of frost have gone down and not when hydrangea macrophyllas break dormancy (they like to awaken early sometimes); fertilize per label directions and then water (if the soil is dry before you fertilize, water then fertilize then water again). You can amend the soil to acidify it at most any time of the year but, do not use diluted vinegar for this as the hydrangea roots are shallow, tiny and in the top few 10 cms so the diluted vinegar solution can act as a herbicide for weed control sometimes and injure the roots. Fertilizers that you can try: organic compost, composted manure, cottonseed meal or a general purpose, slow release, chemical fertilizer with a NPK Ratio of around 10-10-10.

 

Hi,

Thanks for your message. I used about 3 handfuls of the Vitax Hydrangea feed and watered throughly. (Also, picked off the purple looking leaves) but as shown in my pictures, more has come back.

All the best,

Kieran

 

Hi,

Thanks for your message. All the nearby plants seem to be fine (lavenders/ Japanese acer etc). Yes, it is in a soil patch and not potted.

As this is fairly new to me I picked off the purple looking leaves before applying the feed but as shown in the pictures more leaves have now turned purple with the addition of some leaves wilting and going brown since the feed. The soil is generally really moist and doesn’t dry out. I’m just concerned I may have over fed them.

Thank you.

Kieran

 

Depending on how much you added (if beyond the product label's instructions), you could physically remove the excess with your fingers (I am hoping you have not spread it thinly everywhere, though). Too much fertilizer for this type of plant can include a lot of sulfur and salts and that can burn the tiny, shallow roots so be careful. Feel free to try to dilute the excess with water too.

 

Thanks for all your messages. I really appreciate it. I've given the excess fertiliser a good hose down to spread and hopefully it'll wash away..

Hope the Hydrangea will be okay. I probably need to learn to be more patient when it comes to gardening.