Brown Hydrangea Leaves

June 4, 2008 | By | Comments (12)

Hydrangeas
Q: I live in Houston, TX and I have a few summer blooming hydrangeas planted in my front flower bed (which faces north). Some of them are browning on the leaves (even though they get water every day) and some are doing fine. Do you have a good tip for keeping them alive during the hot summer? I also have a bunch of Lily of the Nile. What is a good fertilizer for them? Melissa Comer

A: Hi Melissa,
You might want to check your hydrangeas for spider mites. These tiny pests usually congregate on the undersides of hydrangea leaves when it gets hot. They look like tiny red or brown specks, they move when touched, and they build tiny webs. They suck the juice from the leaves and cause them to bronze, brown, or look speckled. You can treat them by spraying all leaf surfaces with insecticidal soap or horticultural oil according to label directions. As for your lily-of-the-Nile, feed with a slow-release, bloom-booster fertilizer, such as 10-20-10 or 15-30-15. The ratio of nitrogen-phosphorus-potassium should be 1-2-1.
Good luck,
Grumpy

Q: Good Morning –
I found your email address while viewing Southern Living online and going to the garden section. I read with interest about when to prune my butterfly bushes. Thanks!

I have a common question concerning my hydrangeas blooming pink instead of blue. I purchased them while they were blooming and they were blue.

I know it is all about the soil — acid for blue blooms — I have watered them with aluminum sulfate — and they continue to bloom light pink.

Question 1 — Am I using the correct product — if so, how often do I water with this and when do I begin?

Quesion 2 —When do I prune my hydrangeas so I can be assured of blooms the following year?

Thanks for you time and I look forward to hearing from you.
Lavonda

A: Hi Lavonda,
Because your hydrangeas were blooming blue when you bought them and have now turned pink, I would guess you have somewhat alkaline soil. Making the soil acid will take time. You probably won’t see a difference this year. Repeat the applications of aluminum sulfate a couple of more times, but don’t overdo it, because too much aluminum in the soil isn’t good for plants. You could also apply garden sulfur to the soil surface around your plants and water it in. And if you’re a ground coffee drinker, save the grounds and spread them on the soil around your plants to acidify it. Once your hydrangeas start blooming blue, you may have to repeat the application of sulfur every couple of years to keep them that way.
Grumpy

COMMENTS

  1. Carolyn

    Grumpy Gardener,
    Please tell us how and when to fertilize hydrangea.

    July 24, 2008 at 5:46 pm
  2. Grumpy

    Let the Grump say a few well-chosen words about fertilizer. For years, we gardeners have been brainwashed into thinking we can’t grow anything with fertilizing it. After all, corn farmers feed their corn, don’t they? Cotton farmers feed their cotton, don’t they? So don’t we have to feed azaleas, hydrangeas, and marigolds too?
    The reason corn and cotton farmers have to fertilize each year is that growing and harvesting the same crop from the same spot each year depletes the nutrients.
    But we don’t harvest hydrangeas and azaleas, do we? Therefore, as long as we build good, well-draining soil, and add organic matter every year, we don’t need to fertilize our ornamental plants every time we step out of the door.
    A couple of caveats — if your soil is neutral or alkaline and you want to grow an acid-loving plant like an azalea, you will need to use an acid-forming fertilizer or soil amendment. You’ll also need to acidify the soil if you’re trying to turn pink hydrangea blooms blue.
    Don’t cringe, Carolyn. I’m not mad at you — just grumpy as usual. If you don’t have good soil now, you can always start working on it. Any organic matter you can add will help your hydrangeas. You really can’t add too much. In the meantime, you can goose them with slow-release azalea-camellia food if you want blue flowers.
    But don’t fertilize now in the cauldron of high summer. This will encourage more leafy growth and stress your plants when it gets hots and dry. I would feed them in early spring and maybe again in early summer.
    Grumpy

    July 25, 2008 at 11:14 am
  3. Amy

    My hydrangeas are totally brown after 4 nights of below freezing temps. Any chance they will come back? The azaleas in the same bed look fine.

    January 14, 2010 at 2:45 pm
  4. Grumpy Gardener (His Magnificence)

    If they still had foliage when the freezes hit, chances are they’re in pretty bad shape. At this point, what you need to do is determine the extent of the damage. Don’t prune yet. Scratch the bark on the stems to see if you can find the green cambium layer. Green means the stem is alive; brown means it’s dead. In early spring, your hydrangeas should start to leaf out (provided they’re alive). When they do, note the highest point on each stem where growth appears and cut back to just above that point.

    January 18, 2010 at 8:49 am
  5. Nancy Glynn

    The leaves on my Hydrangea curl up on the edges and turn brown. It is budding right now with very few leaves. I’ve checked for spider mites and have seen no trace. What am I doing wrong? Is it OK to cut effected leaves off?

    April 19, 2012 at 6:18 pm
  6. Nancy Glynn

    The leaves on my Hydrangea are curling inward and turning brown. No sign of mites. What am I doing wrong. Is it OK to cut effected leaves off?

    April 19, 2012 at 6:20 pm
  7. Grumpy Gardener (His Magnificence)

    Your hydrangeas don’t sound very healthy. It’s a little too early to be having mite problems. If the leaves are curling and dying, it’s OK to remove them. You haven’t used any weedkiller near them, have you?

    April 20, 2012 at 12:16 pm
  8. Luwana Carl

    Hi I have two hydrangeas that have been doing great for about 4 years. This year some of the leaves seem to be smaller and are curling and some are turning brown around the edges; then there are some that look great and are showing the beginning of the flowers. What am I doing wrong?

    May 19, 2012 at 4:39 pm
  9. Grumpy Gardener (His Benevolence)

    Luwana,
    Your plants could have spider mites. Looks closely on the undersides of the leaves to see if you spy any tiny specks that move around and any tiny webs. If you find these, use a strong spray of water from the hose to blast off the mites. If the problem persists, apply Bayer Advanced 3-in-1 Insect, Disease, & Mite Control according to label directions.

    May 21, 2012 at 9:22 am
  10. Kathy

    Help! My husband and I bought this house in March. The hydrangeas leafed out nicely and bloomed well. All of a sudden they have brown, brittle leaves, and are covered in webs. It’s obviously travelling from one bush to another as the one on the right is not as bad as the one on the far left, but all are affected. Tonight we noticed a brownish/orangish “dust” of some sort on the leaves. We don’t know what we’ve inherited and have no experience with hydrangeas. What do we do?

    September 8, 2012 at 10:25 pm
  11. Kathy

    P.S. The mold/fungus stuff is on the top of the leaves. The leaves and the dying flowerheads are covered all over with webs.

    September 8, 2012 at 10:28 pm
  12. Steve Bender

    Kathy,
    My guess is that your plants have spider mites. These pests are very tiny and hard to see, but the webs give them away. To kill them, spray your plants according to label directions with horticultural oil or insecticidal soap. Be sure to wet both upper and lower leaf surfaces.

    September 10, 2012 at 2:54 pm