Comments on: Rosemary care

By: Mary Ellen Williamson

Mary Ellen Williamson — Mon, 08 Mar 2010 16:54:20 +0000

Powdery mildew
My rosemary plant was bought at Christmastime and has done very well. I am following the directions that came with it which said to give it one cup of water daily. In the last week it has developed a white powdery dusting on all the leaves. Could you please tell me what this is and how do I get rid of it? Is it harmful to the plant?

Hi Mary Ellen
See http://hortchat.com/info/powdery-leaves-on-my-rosemary-plant

By: Ellen

Ellen — Tue, 02 Mar 2010 23:17:25 +0000

Browning needles
I have a rosemary Christmas tree that was doing fine in my west-facing office window, but I forgot to ask my assistant to water it over the holiday vacation, and it’s fairly brown. I know they are slow-growing, so I’ve been hesitant to cut it back entirely. I’m not sure how to tell if it’s totally dead.

Hi Ellen
If your rosemary is brown, then its dead. sorry

By: Mark

Mark — Tue, 19 Jan 2010 20:11:00 +0000

Soluble salts
I have a small potted rosemary plant that’s indoors for the winter. The clay pot continues to have a yellow and white residue all over it? When you try to clean it off, it just comes right back.

Any ideas as to whether this is the plant, soil, pot, or water source? And is it harmful to the rosemary? What can I do?

Hi Mark,
The yellow and white residue on the clay pot is a result of soluble salt accumulation. This occurs from fertilizers, or water with high amount of minerals. You can try scrubbing the pot with vinegar to remove the buildup on the outside. In the spring, remove the plant and thoroughly wash the clay pot with vinegar,soak, rinse in clean water and let it dry in the sun. It should elliminate most of the salts. Too much salt accumulation can eventually harm the plant. To avoid this problem, flush out the salts by running water through the soil so that it drains out from the bottom. Do this several times and each time you water. The excess minerals/salts will wash out. I would also re-pot the rosemary plant in fresh soil in the spring.

By: Jason Ng

Jason Ng — Mon, 28 Dec 2009 08:48:57 +0000

Rosemary in hot humid weather
Hi i am from malaysia, i love rosemary and use normally in my cookings. Last few months, I bought one potted from a hypermarket (Jaya Jusco), eventually it died, it went all brown on the leaves and then dried up. Being ignorant, i thought it was insufficient water, as most of the time, when u see a plant turning brown, it means drying up and needs water. So i water it too much eventually I killed it.
I found another pot again, this time at another hypermarket (Cold Storage – Ikano), and this time i dont water it much except for spraying like mist water to it. Eventually it turning brown now, especially the bottom leaves.
I have the plant indoor, in my kitchen to be specific, and it was not under direct sun or rain. Is this a problem?
Malaysia is a tropical country, very high humidity, but does this affect the rosemary? I only know that rosemary can withstand the most dry season ever… Malaysia is hot for your information.

Hi Jason
Moisture to heat can be the problem. Try watering the rosemary plant less often but give it a good soaking when you do and then drain out any excess water. Water again when the top 2″ feel dry or the pot is light.
Make sure that the soil is well-drained. Skip misting-that can invite problems such as powdery mildew especially in humid weather. The plant will appreciate a good rain as long as it can get a good breeze to help it dry out. In extreme heat, place the plant in a shaded area for cooler temperatures. I hope this helps.

By: Jean Zastrow

Jean Zastrow — Mon, 30 Nov 2009 16:30:44 +0000

I live in Memphis and my Rosemary is in a very large plastic pot on my East facing patio. Do I move the pot indoors or will it survive the winter on the patio. The temps can drop below freezing. Should I move it to a Southern location protected from the wind or move it indoors to the garage or florida room?

Hi jean
Rosemary can tolerate cooler temperatures but not freezing. It could survive outdoors in Memphis but would need to be protected in case of a frost. A Florida room would be an ideal place for it to winterover in.

By: Werner

Werner — Sat, 31 Oct 2009 08:21:45 +0000

Hi,

I’m looking for some photos of rosemary diseases. Any of the following will do:

Alternaria
Armarillia tubescens
Botrytis
Powdery Mildew
Pseudomonas
Rhizoctonia sp.
Sphaerotheca fuliginea

I grew a Rosemary brush from a seedling. It started of well but now the tips of the leaves are turning brown and the stems are also losing leaves. I’m not sure whether it’s from overwatering (it’s potted) or whether it’s a pathogen, but I’d like to compare the color and texture of my ill leaves to some photos of known problems. Is there a site were I can submit photos of the plant for diagnosis?

Hi Werner
Contact your local extension office. They may be able to help.
It possible that it is a water problem. Take the plant out of the pot and see if it has some cream colored roots, also check the soil is it soak, soggy? Are the roots potbound? If pot bound, sometimes just cutting off some of the bottom layer of roots and repotting in fresh soil can help the plant recover.
A stressed rosemary plant is susceptible to powdery mildew.

By: Cheryl

Cheryl — Sat, 26 Sep 2009 15:59:20 +0000

Hi, I've had a Rosemary plant for the past year and a half and have kept it indoors the entire time with zero problems. I kept the plant inside out of necessity since I live in an apartment. However, recently my plant somehow got exposed to some small, flying insects and now those insects can constantly be seen hovering around the plant. Additionally, I think they might be harming it since certain needles have started to turn brown, a problem that I had never had previously. My question is, how can I kill these bugs without using any harmful chemicals (since I like to use rosemary in my cooking and don't want to ingest any of the chemicals)? Thank You

Hi Cheryl Are these insect hovering about the soil? Could they be fungus gnats?

By: Janet

Janet — Thu, 20 Aug 2009 11:48:36 +0000

Thank you for your prompt replies. The rosemary plant has actually perked up since my first question was posted. My rosemary plants have about two months left to soak in the glorious outside and then they will be brought into the house to winter over. I feel pretty good that here in northern Maine I have successfully wintered over several rosemary plants on my first attempt and that I have all of them to try again this upcoming season. Wish me luck….

Hi Janet
Glad to hear that it perked up. Rosemary can be difficult to winterover indoors- Kudos to you.

By: Janet

Janet — Wed, 19 Aug 2009 11:08:48 +0000

The plant was transplanted into a nice new pot with fresh soil this spring. There are no insects on the leaves, so it must be a fertilizer issue. What type of fertilizer should I use on my rosemary and how often?
Very needy plants these rosemary trees, but they are a beautiful addition to my deck/garden. I bring them in during the winter and so far have successfully kept them through a northern Maine cold snap.

Hi Janet
They don’t require a lot of fertilizer. At this time of year, give it a dose of 10-10-10 or fish emulsion once a month. Stop feeding by Oct. Since we’re going into the fall season, one feeding may be sufficient.

By: Janet

Janet — Tue, 18 Aug 2009 12:44:26 +0000

Yellow leaves My rosemary tree has been doing great up until about a week ago. It sits on the deck outside and I water it regularly. It has been nice and thick, very fragant. I noticed yellow leaves a few days ago, too much water or not enough?

Hi Janet It's possible that your rosemary plant may be rootbound or needs some fertilizer which can cause the leaves to turn yellow. Insect infestation like whitefly and spider mites can also cause yellow leaves. If you overwatered and kept the soil soggy, the leaves would turn brown and drop.