lily51
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Does anyone grow herbs during the winter in a greenhouse?

I live in Ohio and have a small heated greenhouse. Last year I thought it would be nice to have herbs in it during the winter. I didn't have much luck.
I started them in the fall so they would be growing during the winter in there. Was it too cool? Not enough sun?

The ones I started in Feb and later did just fine for planting outside or for growing in pots.

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lorax
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It's possible to do, but it often gets too cold in an unheated greenhouse. My main question would be Why? since herbs make ideal houseplants.

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rainbowgardener
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Lily did specify a heated greenhouse.

So I don't know what happened to your herbs, depends on so many factors, was it too hot, too cold, not enough sun, over watering (many herbs like to stay on the dry side), too humid, etc.

Depends on the particular herbs as well.

Rosemary is particularly fussy about over wintering. I have killed two rosemary plants already, bringing them indoors for the winter. If you use the Search the Forum feature you might be able to find a thread we had about overwintering rosemary last year. I'm going to try again this fall with a new rosemary plant I started from seed this year, but I'm going to switch out the potting soil for something sandy-er and then water very little, just mist it.

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applestar
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Right, they'd do better in 50's as would lavender, thyme, and sage, but basil needs to be 60's at least and sulks at a touch of cool draft and turns black from cold. We need a list of the herbs you grew and max/min temps in your greenhouse. We'll assume you checked them regularly and watered, etc. :wink:

lily51
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My greenhouse is heated with propane, but my early batch of basil didn't make it. However, I tried several basils for spring and summer and they did great.

The sage started, but it is a slow grower and they all eventually died.

The rosemary I was able to keep growing, but it is sooooo slow you evidentally have to keep them going for a couple years. Also, it did not germinate well, even in the house.

The thyme started okay, but it all died also. Looked like root rot so with the cooler temp and little winter sun maybe it was too wet? I wanted a lot of thyme to do some patterns in my raised beds, and that did not happen.

I just thought it would be neat to have lots of fresh herbs growing over winter, like walking into another world from the cold, dreary Ohio winter.

Any suggestions?also thought perhaps I could find a way to sell them .
Maybe it wouldn't even be possible with the annual herbs; and maybe the perennials need some dormancy.
Any advice is greatly appreciated.

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rainbowgardener
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But at least in my part of Ohio, lavender, thyme, and sage can just stay in the ground all winter. Rosemary is the only one of those I bring in, because it is the only one that isn't hardy here in zone 6. Of course the lavender, thyme, sage do go dormant in the winter. I'm thinking that in the greenhouse you could keep them going all winter, because they are warm climate plants. But they don't like too much humidity.

Susan W
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This is a topic of interest to me as I am expanding my herb pots. I plan to have several basil pots inside for the winter. Does not like to go below 40. I had a couple winter for me last year by a window. As I add more, get get a light fixture and put the squiggly bulbs in it.

Rosemary can have problems being moved in and out as noted. Mine is out, in the ground. I have another doing nicely in a pot and may pull it up next to the house for the few colder weeks.

Bay 'mini tree' comes in.
I may bring one thyme pot in, leave rest out. Then see if I can harvest all winter.
Chives may need a down time. In checking on the net, saw they need a couple months down. Given that, may leave out until Feb, bring in and let them start growing and greening early.
Don't know if mint needs a down time.

As for selling, had one small restaurant. They quit ordering, and I hit another one, again. They have new chef. Hopefully we can get a working
relationship. I told him the selection won't be as great in winter. I had made another visit with fresh gifts -teasers. Had not heard, so called the chef. My basil needed cut back bad and I made an offer not to be refused! (1# fresh picked basil!) When I think about putting some back for myself, realize I will have the plants fresh in the house!

Back to the question. Trial and error, I am great at both. See what will do in the greenhouse, and as you worked it last year, get some starts going ahead of the game. Then try to hit the restaurant/farmers markets/other venues come spring.

fannyfarmer
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I have propagated and grown herbs under lights indoors and in a midwest greenhouse for many years. First.....the soil should be 5.6 to 6.5 ph as a general rule.
Overwatering is the big killer AND short daylight. A 10 to 12 hour light schedule is best....that may be why your herbs started to do better in the spring when the days become longer......
The bagged soilless medias work wonderfully well....Jiffy Mix or the Miracle Gro brands should all be ok.
Trimming overgrown herbs is a must to keep them going.

Some herb seeds benefit from soaking and / or exposing to light. (I have a chart I created for most common herbs in this regard and can try to reproduce it here if you like)

All this should be considered and don't get hung up on temps too much. 60 to 80 degrees will handle most things. 40's and 50's not so much. A night or two down there is ok, but not as a daytime temp.
Watch for insects......Organic pesticides ONLY!
Go forth and multiply!
:D

fannyfarmer
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I forget to ask if the propane heater is vented outside the greenhouse. Propane fumes inside the greenhouse are too much for plants and will cause problems and not good for folks either! :?:

Susan W
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Thanks for tips, ff. Can you share tips about which herbs did better, not so well, or need down time?

Last year about this time I got new basil starts at the box store, and potted up for the indoor ones. I left them out until end of September.

Agreed that over watering is a killer for many.

fannyfarmer
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Basil is so cheap and easy that it really was easier for me to keep starting it in series and by the time it tried to flower, I pitched it since there were plenty more coming along.

Ditto Sage and oregano.

Thyme was a headache and will fold with the least overwatering or dark weather.

Cilantro and parsley needs to be soaked for a couple of days before seeding to get better germination. And even then may be sparse.

2nd growth parsley can turn bitter in a flash so I never kept it over.

Cilantro is best when young so you have to keep seeding in series.

Mints are all easy, but can take over fast, so I kept them trimmed..

Rosemary is slow and difficult for beginners and can die from too high humidity or if you look at it crosseyed! Too bad it is VERY popular with chefs now, so if you can keep it going....you should get a premium for it fresh.

Dill weed is always in demand for fish restaurants and is fast and easy, but be sure to use the dill WEED seed which doesn't head up.

French Tarragon is a slow grower, but not fussy.

Always have a pot of chives going....they are quick and should be seeded in groups for a nice lawn-like stand.

Stick with the basic herbs and they will sell faster....

And always be on the lookout for whitefly......the bane of the greenhouse!

lily51
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Thanks for all the ideas.
As for the heater, it is part of a heating/ventilation system set by thermostats, not just one set in the greenhouse. That was a concern when choosing a heating method, but it has worked out very well.

Once poinstettias are done, I'll try my herbs again. I have a stand that holds 12 trays with grow lights above, so might just keep them under that for more heat than just greenhouse heat. Also will watch the watering.

No matter what, it's fun to experiment.



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