Need help overwintering lavender indoors! +Rosemary how-to.

[applestar]

OK, I think I got the Rosemary overwintering down after 3 successful winters. the ones I brought in for this cold season has acclimated nicely and are starting to grow new shoots.

HOWEVER! One clay pot of lavender cuttings that I started last spring, which I felt was still too small to withstand the winter outside, is rapidly deteriorating.

I've been giving it the similar basic care as Rosemary, but obviously, it's not quite what it wants. I've now swapped it out with one of the rosemaries that had the prime spot closest to the window in case it wants more light and be cooler.

There doesn't seem to be many threads here about this topic. [url=https://www.helpfulgardener.com/forum/viewtopic.php?p=32244&highlight=lavender+indoor#32244]This[/url] was the only one remotely close I found. Experienced advice would be most appreciated.

[applestar]

Any insights for keeping my lavender alive? I'd really hate to let it die, though now that I've done it once, I can root more cuttings next spring....

[rainbowgardener]

Sorry, I'm not being helpful. I've never brought mine in. I'm in 6b and my lavender stays outside all winter, even the stuff in pots. It sets it back, so it never gets as big as the gorgeous lavender shrubs I see in Calif, but it survives.

If your lavender isn't doing well inside, maybe you can find a nice protected spot against a south wall or something and let it stay out?

[lorax]

Lavender likes a bit more abuse than Rosemary - find it a bright window that's a bit chilly, and cut back on the watering. It will slow down, but it won't grump out and die on you this way.

[applestar]

Thanks for your replies Rainbow and Lorax
OK, tough love, it is!

[applestar]

IT'S ALIIIIVE!!! I put the container just below windowsill so cold air will pour right over it.

The lavender is sending up pale spindly shoots. Not ideal, but maybe if I can keep them alive, this will work. If it doesn't, next time, I'll put one out in the garage close to the interior wall and see if it will stay dormant over the winter.

[rainbowgardener]

I still don't think I have the secret of wintering over rosemary... I've been misting the plant (heavily) once or twice a day and never watering otherwise and have a CFL shining right on it. Given all this, it is not dead (I think), but clearly not doing well, and no new growth.

I don't know what it is, all kinds of other plants do just fine for me indoors (my angel trumpet that I started from seed 3 years ago is actually BLOOMING indoors!), but I just can't get rosemary to make it through the winter. I do fine at starting it from seed and it thrives all season outdoors and then it just sits around and dies slowly when I bring it indoors.... oh well, I guess you can't win them all!

[applestar]

In addition to daily morning misting, I give the rosemary in 8" pots about 1 cup of water when the soil surface is dry. 6" pots get 1/2cup and 4" pots get 1/3 cup (they dry out faster). Rosemary are all in clay pots and I probably water them every other day or every 3 days. I use filtered water for misting and mostly chlorine outgassed tap water for watering. (Also occasional rice washing water or UCG water, etc. -- not too much of UCG water since rosemary won't like acidified water.)

They are all growing pale new shoots, which I keep pinching and using. All the rosemary will get a severe pruning when they are put outside in spring. I've also started training 2 of my 4" pot rosemary into a small standard. (I think Bewildered got me started on this NEW PROJECT ) If they turn out well, I'll get the pair of them fancy little urns or something to grow in.

The rosemary are on -- or on an 18"H table (made of shelfboard on stools) 6" below -- the sill of a first floor SW widow along with the lavender. Most of my citruses are using the sunlight from the same window on a 28"H sofa table (they have a supplemental CFL).

This is in the Family Room so they also have reading quality ambient light until bedtime. This room also has a SE facing window (where some of my stub pruned overwintering peppers are on a 36"H surface near a forced air heat vent) I have another CFL here, but I'm going to get additional supplemental light for the rest of the peppers that are coming in from the garage very soon.

[applestar]

I had the thought just now, rainbowgardener, that if your rosemary is in a colder location, which I think you said elsewhere that they are, they might be in dormant state and won't accept too much additional water. (You said there's no new growth) It'll be interesting to see if this works out for you. I don't have anywhere else that would meet their temp/light needs, and this particular window is now RESERVED for the rosemary every winter.

[rainbowgardener]

what counts as a "colder location"? I'm guessing part of the problem is temperature variations... We have a programmable thermostat which sets the house down to 59 over night AND in the day time when we are at work. Then it goes up to 68 for a couple hours in the AM and some hours in the evening and some extra hours on weekends. So it's constantly going back and forth from cool to warm. The rest of my house plants seem to tolerate this pretty well, but maybe it is part of what the rosemary doesn't like. I could try to find a spot that would stay cooler (might involve putting a light in the coat closet in the vestibule/ air lock entrance! )

[applestar]

Don't go by the thermostat -- it only indicates the temperature immediately around it. Do a little detective work around the house with a thermometer and hunt down temperature micro-climates. (Which is the reason I indicated the height of tables in my previous post).

The windowsill in question is currently 54ºF (Double-glazed window. Exterior temp 27ºF). The interior edge of the 18"H table is 58ºF after overnight 62ºF thermostat setting. (This is almost meaningless though, since the thermostat is on an interior wall 3 rooms away, at eye-height for a 6 ft individual ). The humidity is 60% here, much higher than the rest of the house which will steadily decline over the winter but is currently around 50%. After thorough misting, the humidity around the plants rises to over 70% (74% right now).

Your 68º bursts are probably for warming up the house so you can be comfortable when you're in, and depending on the relative location of the thermostat to the rosemary, you'll still have cooler temps. (Be aware that there will be locations *warmer* than 68º as well.) I have my thermostat set to run at 65ºF just before dawn and in the evening until we're tucked in bed for the same purpose -- this brings the upstairs temp up to around 67ºF.

The the forced hot air heat vent closest to the rosemary is probably the farthest on the first floor from the air handler unit (not counting the vents upstairs, but temp upstairs is always higher since warmer air rises). And I have it partially blocked so the air is directed away from the plants.

Since the outside temp is getting lower (we're now settling down to normal Dec weather of 30'sH/20'sL) I'll be setting the thermostat a little higher to compensate. I expect we'll be getting regular lows in the Teens and some single digits starting around New Year's Eve.

[rainbowgardener]

yeah... it's complicated. Question is what am I aiming for? What temp would the rosemary like to be at?

[applestar]

Ha ha. You got me hunting down my favorite indoor garden book: Well-clad Windowsills — Houseplants for Four Exposures by Tovah Martin.

First let me pull a quote from her Rosemary section:

...there's an old English adage concerning homegrown rosemary: "If rosemary thriveth, the woman ruleth."

(Yeah, I thought you might like that, and inspire you. )

She states that Rosemary wants cool temps at night.

When the thermometer shoots above 55 degrees Fahrenheit after dark, it begins to look straggly. It requires a south-facing window and more humidity than most herbs.

[applestar]

Pictures!

Lavender trying to come back. You can see a new rosemary shoot in the right foreground:
[img]https://i290.photobucket.com/albums/ll272/applesbucket/Image8269.jpg[/img]

Most of the rosemary. A little hard to see but two 4" pot topiary training rosemary are sitting in the large bulb planter with group-planted citrus.
[img]https://i290.photobucket.com/albums/ll272/applesbucket/Image8268.jpg[/img]

I posted the main citrus grouping photo [url=https://www.helpfulgardener.com/forum/viewtopic.php?p=173115#173115]here[/url].

[Susan W]

My lavender and rosemary stay outside. Small ones may not make it. Well, I have lost them in summer due to wet feet!
I think the watering is key, as well as light and temp. They slow down in winter, so less water. But how much is too much or too little?!!
As for temp, both take cold, so being by a chilly window could be good. And may break some draft coming towards you!

Also, the bigger the pot, the more the water is moderated, so doesn't dry out totally then get watered.

Just some thoughts. And thinking I have one rosemary in a smallish pot that I may coddle and bring in when cold.

[rainbowgardener]

My lavender stays out, but the rosemary can't handle the zone 6 winters...

thanks for the tips all!

[rainbowgardener]

My rosemary is not only not dying, it is actually putting out new growth now! YAY!!

What I've been doing: misting daily, watering with one cup of water (not very much for the size pot it is in) every other week, with 1/2 tsp baking soda in the water. It seems like the soda water is really making a difference. Before I started doing that, it was just hanging in there, not dying, but not growing. Also I do have supplemental light on it; I don't have a sunny enough window (and Cincinnati is very gray in the winter anyway).

[applestar]

[rainbowgardener]

Thank-you, thank-you (takes a bow ). I'm so pleased, having killed a couple beautiful rosemary plants in the past. I think the baking soda treatment is necessary, because it is just planted in potting soil with peat in the mix, so probably on the acid side. If I had planted it in a more sandy, cactus type mix, it might not need that.

[hydroguy]

Great thread and I found it in such a timely manner. Insights from 2 of the most respected members here at HG in my opinion. Maybe you folks can help me determine plant densities for both Rosemary and Thyme, think I've got the lavendar sorta figured out now that my second batch is coming along nicely.

The plants will be grown in 6" net pots, how many plants per pot is what I can't figure out by looking at all the images. Rosemary looks like it might bush out so maybe 2-3 plants per pot, the Thyme I have no idea. These plants will remain in doors in these pots for their entire lifecycle and like the name says, grown hydroponically.

Any thoughts would be GREATLY appreciated, seeds will be here first of the week and will be planted then.

So you have an idea of the space I'm dealing with and size of containers here's a shot of an identical system the plants will be grown in.

[img]https://i784.photobucket.com/albums/yy130/hydroguy/Hydro%20chamber%201/CopyofPICT0046.jpg[/img]

Thanks in advance,
hydroguy

[lily51]

Just talked to a man from master gardener who has had success this year over-wintering rosemary inside (here in Ohio, zone 5b). sounds a lot like your method, but just the reverse. Waters each week, mists with a weak baking soda solution.

So why is baking soda the magical compponent?
I'll try it next year.

[applestar]

hydroguy, I'm still amazed you can grow lavender, rosemary, or thyme hydroponically. It has to be Ebb and Flow with longer drain/drying cycle right? I imagine the inevitable higher humidity might actually help with the rosemary, but I'm not so sure about lavender or thyme.

I don't know what would be the most appropriate density, but to give you an idea --
Somewhere on the forum, cynthia_h mentioned her rosemary SHRUB in her California garden that I think she said is 6 FEET wide.
Lavender, as far as I know, doesn't get quite as big as that, but we're still talking about 18"~24" across, I think. I'm pretty sure lavender likes it even drier than rosemary.
Thyme could handle a much denser planting than either of the others, obviously. I had 4 growing in a 4 inch container, but when I left it directly on the ground, it grew roots right down into the ground and then cascaded over and rooted all around the container!

--

lily51, For me, maintaining higher humidity and moisture level for rosemary has been the key. It may have to do with the forced air heat causing severely depleted humidity level during the winter. But many people have said that rosemary is susceptible to powdery/downy mildew or white mold. Perhaps the mild baking soda solution is to prevent the fungal attack. I add a pinch~1/8 tsp in my 32oz sprayer once in a while if I feel like I've misted my plants too late in the day for them to dry out properly and they might be inclined to get some kind of fungal disease.

I tend to prefer the 10% Milk Solution for anti-fungal prevention, especially outdoors, but for indoor plants that I'm not up to moving into the bathtub for the treatment, I use the baking soda solution, since spraying even dilute milk on the furniture, walls, or carpet is not very appealing.

[rainbowgardener]

lily51, For me, maintaining higher humidity and moisture level for rosemary has been the key. It may have to do with the forced air heat causing severely depleted humidity level during the winter. But many people have said that rosemary is susceptible to powdery/downy mildew or white mold. Perhaps the mild baking soda solution is to prevent the fungal attack. I add a pinch~1/8 tsp in my 32oz sprayer once in a while if I feel like I've misted my plants too late in the day for them to dry out properly and they might be inclined to get some kind of fungal disease.

I tend to prefer the 10% Milk Solution for anti-fungal prevention, especially outdoors, but for indoor plants that I'm not up to moving into the bathtub for the treatment, I use the baking soda solution, since spraying even dilute milk on the furniture, walls, or carpet is not very appealing.

Ugh... yeah, the milk treatment can be a bit stinky! But I'm doing the baking soda to keep the soil alkalinized, which is what the rosemary likes (lavender too, but I don't bring my lavender in, it stays in the ground). I have the rosemary just in potting soil, with a lot of peat. As I mentioned above, if I had it in a sandy cactus type mix, I probably wouldn't need the soda. But yes it definitely needs more humidity than indoor air. A number of my house plants are benefiting from the daily misting - my angel trumpet, a rain forest plant, loves it and is doing so much better this winter than other years when I wasn't misting so regularly or thoroughly.

I don't know anything about hydro-growing and how much more you can crowd things than if they were in soil. But as AS noted, both lavender and rosemary are good sized shrubs, especially if they don't have a winter die back.

[rainbowgardener]

So I think most rosemary is hardy down to 15 - 20 degrees. It being almost March, we are through the worst of the winter and not likely to see too much of those temps again, though we will still have some frost. What do you think about whether my rosemary could be moved out now (if I see real cold coming in the forecast, I can always bring it back in again; it is in a pot)?

I turned all the lights on the house plants off, when I turned them on in the basement for the seeds, just because I feel guilty about all the electricity my gardening projects use. Since the lights went off (and I've been a bit less regular about misting, because I 'm busy caring for the seedlings), the rosemary is suffering more, just not enough light. So if it wouldn't mind later winter kind of cold, it might like it better outside?

[applestar]

I don't know, I think I would wait just a little longer, especially since your plants has spent the winter indoors and are not acclimated to the severe cold...
But why not put the rosemary somewhere near the seed starting area? There must be a spot it could get some extra light?

[Susan W]

I agree to baby your rosemary. If you see several days/nights with lows in upper 20-30 range, pot may be OK outside, sheltered near house. If hitting a colder spell, bring in.

Rosemary has deep roots, so perhaps this spring could pot it up to bigger/deeper pot. But keep in manageable pot size that you can bring in next winter!