Can you be my herb doctor?
December 13, 2007 12:12 AM   Subscribe

What happened to my little herb garden? They were growing really well [1] [2] [3] [4] (just-watered), and then they've sort of died off [5] [6] [7] [8]. I've been growing them under my oven light. Can you help me figure out what went wrong and if I can save my herbies?
posted by lpctstr; to Home & Garden (20 answers total) 5 users marked this as a favorite
Your oven light, you say? What's it like, this oven light? Your wee plants want the equivalent of sunlight, not a standard incandescent bulb. You need to get some grow lights, or move the herbies to a windowsill (preferably south-facing) where they'll get sun.
posted by mumkin at 12:29 AM on December 13, 2007

lpctstr;, what were you growing? cilantro, basil? What kind of mix is in the pots? How often did you water them? If they were growing under the light above your stove, how consistent were the conditions there? and, e.g. what happened to them when you cooked on your stove? Your taller sprouts do look like they were stretching for light, as mumkin suggests. (Sorry to bombard you with questions, it just might help us help you figure out what happened...)
posted by onoclea at 12:37 AM on December 13, 2007

My first take was also not enough sunlight. Or one image looks like the result of them totally drying out, but if that was it, I'm sure you'd know.
posted by salvia at 12:41 AM on December 13, 2007

It's not just a lack of sufficient light. They're not getting the right kind. Incandescent lights are most strong in red and yellow. Plants need blue light, and plenty of it. Your oven light not only isn't remotely bright enough, it's producing the wrong frequencies.

The pictures that show really long stems with only a few leaves? That's a sign of a stressed plant, desperately reaching out in hopes of getting its leaves outside of the shadow it found itself in. That's not "growing really well" that's "I'm one step from death".
posted by Steven C. Den Beste at 12:45 AM on December 13, 2007

Looks like etiolation to me. I'm guessing that it's winter and natural light is in short supply in your location right now. If so, you need to wait a couple of months then try again in a warm bright spot. Or buy a growlight, but IMO don't waste the electricity.
posted by singingfish at 12:46 AM on December 13, 2007

The oven light is just the bulb on the oven... I think an incandescent. I've moved them to the balcony a few times and it didn't do anything at all. In fact, it's kind of cold outside for that. I know the oven light works because in the beginning, the plants always grew towards the light and could change directions in only 8 hours.

I'm growing a pot of each -- basil, cilantro, chives, thyme, parsley. I watered them about once a day. I moved thme off the stove when I cooked of left them there when i just needed one stovetop.

I'll try doing the windowsill thing some more, but I don't really get that much light because of the balcony.

Thanks for the suggestions so far.
posted by lpctstr; at 12:46 AM on December 13, 2007

I can understand how it might seem like the incandescent was working because of the way the plants grew towards it. For the reasons that everyone's described here so far, though, it's pretty likely that they were stretching towards the light to try to find more of the proper light that they needed. A lot of plants grown inside at this time of year in the higher latitudes will do that. All your sprouts only seemed to have their first leaves. These are the leaves that come out of the seed as it grows, and they are usually much closer to the soil when they are getting enough sun. The second leaves your herbs should have put out would have looked like the leaves of the herbs you were trying to grow, but maybe, they weren't getting enough of the proper light to feed themselves enough to grow them. All this would have really stressed your plants out. If they were on the stove while you cooked, the changing temperatures and humidity might also have stressed them out too. Probably not what you want to hear. Consistency is really important when growing plants, especially new ones. It takes awhile for plants to adjust to conditions so you might not find out quickly whether something is helping or harming them. Just some thoughts. (It's always hard to definitively "diagnose" what happened to a plant remotely.)
posted by onoclea at 1:11 AM on December 13, 2007

The plants growing thin, tall stems is, as everyone else has pointed out, the result of not enough light (and not the right kind). Just because they are growing towards the light source, doesn't mean that they will grow properly under an incandescent bulb. Trying to grow herbs under a regular incandescent bulb is a recipe for disappointment. From the sounds of it, your windowsill isn't going to be much better. If you get a reasonable amount of sunlight on your balcony, you could grow things out there, but they will need to be hardy enough to deal with the cold in your area. If I'm not mistaken, this is one of your earlier gardening attempts. Have you considered hardier plants like spinach or chard?
posted by ssg at 1:17 AM on December 13, 2007

Oh dear, poor editing made that come out quite badly. I meant to say:

... earlier gardening attempts, so have you considered hardier plants ...
posted by ssg at 1:21 AM on December 13, 2007

Your herbs may have shown a positive phototropism towards the oven light, since that's the best they could find, but I'm afraid it's never going to be able to provide them with enough of the right kind of energy. If you're really eager to grow fresh edibles over the winter, I suggest you try growing sprouts (which you've basically already done). Sprouts don't need sunlight, as the seed contains their initial source of energy and you eat them very young. Get a kit like this, perhaps, though you can get by with less. There's a breadth of subtle flavors and textures in sprouts—it's not all alfalfa and mung bean you know—and you can do it without the sun.

If you don't want to be a sprout farmer, a few of these usb-powered mini greenhouses might be interesting, for small scale computer-based gardening. If you daisy-chained six of them together, you might be able to have the herb garden of your dreams (though the lights don't look very powerful). Or there's the AeroGarden, which seems awfully gadgety, but certainly promises to do what you want if the pictures are to be believed.
posted by mumkin at 1:26 AM on December 13, 2007

Okay, so it looks like the general consensus is wrong lighting. For now, I added a tube fluorescent light to its diet, and will try to give it as much windowsill time as possible. If this fails, I'll save up for an AeroGarden, which look like it's about $150.

I like herbs and they are really the only thing I want to grow, but thanks for the other suggestions.
posted by lpctstr; at 1:49 AM on December 13, 2007

A tube fluorescent is still not ideal, because so much of the energy is wasted (from the plant's point of view) producing green light, which plants can't use. You can tell that plants aren't using green light, since that's what they reflect.

What you want is fluorescent grow lamps, which have only red and blue phosphors. They produce the weird-looking light you may have seen over fishtanks or in butcher shops.

For four little pots, I'd recommend two or three two-foot twenty-watt fluorescent grow lamps, with decent reflectors, spaced maybe three inches apart. Position them about four inches above the growing plant tops. Don't use the incandescent oven lamp as well, just use the fluoros; you won't be able to get the oven lamp close enough to make a significant difference to the amount of light the plants get without burning them, because most of the energy you push through an incandescent bulb turns into heat, not light.
posted by flabdablet at 2:04 AM on December 13, 2007

Unfortunately, a fluorescent tube light isn't going to give your herbs the light they need either. It won't produce enough light of the right wavelength. If you want to grow your herbs under artificial light you need a grow light.
posted by ssg at 2:06 AM on December 13, 2007

You can buy a GE grow lightbulb at Home Depot or similar. I think mine cost six bucks CDN and I just use it in an ordinary clip-on lamp for a few hours when my plants are looking ill.
posted by loiseau at 3:15 AM on December 13, 2007

Your oven is extremely extremely ARID. It's sucking the moisture out of your plants as soon as you give it to them. Don't be afraid to set them by a window, herbs are pretty tough little buggeroos.
posted by TomMelee at 5:19 AM on December 13, 2007

FWIW, I have a basil plant that just made the transition inside, and the only window that isn't blinded during the day is about three inches wide. However, it seems to have adapted pretty well and is actually thriving off its very little sunlight. So don't be afraid of the windowsill. Put your plants there, leave them there, and let them acclimate.
posted by General Malaise at 5:32 AM on December 13, 2007

For a cheap and dirty solution to growing inside, try buying a few old desk lamps, and then look for the strongest "energy saver" screw-in flourescent bulbs you can find - 20 or 23 watt. Four should do the trick. Get some of the "white/bright" ones (more usefull blue/white light) and less of the "warm" ones (which are stronger in red spectrum light). This will give you enough of a mix of light spectrums to start younger plants with. Since the lamps can be set alongside the herbs as well as above it, you won't get the stem stretch problem that overheaqd FL lights promote. Also, those "grow" FL lamps are really not much better than a regular "white" FL tube, just more $$.

For better results you would have to do what the indoor marijuana growers do... sodium or Metal Halide lights of at least 200 or more watts. Parking lot security lamps, for example.
posted by zaelic at 7:43 AM on December 13, 2007

Your seedlings are not doing well as they are not getting enough light from an oven light. Also, it doesn't sound like your window light will be enough either as there will be very little, if any, direct sunlight due to the balcony and the fact that it is winter. IMO, you don't need a fancy set-up like an AeroGarden or special plant lights to grow herbs. I went with a set of cool and warm fluorescent lights for my indoor grow-op (self-link). Granted, my experience to date has been successfully starting vegetables, herbs and flowers from seed in the spring for an outdoor garden however I plan on starting indoor herbs and lettuce soon. You can also read more at Garden Web's Growing Under Lights forum.

From your pics it looks like your seedlings are too close together. Were you thinning them out?

If you want to get your next batch of seedlings started quicker you can pre-sprout your seeds. Get a coffee filter (one for each herb), soak it in water and space the seeds out on a quarter of the space. Fold the wet filter in half and then in half again. Place in a baggie, mark it with the type of herb and put it on top of your fridge or on a heating mat (you don't need any lights for this part). Check on them daily and refresh with a spritz of water to ensure the filter is damp. Once a seed has sprouted, carefully transplant to a small pot with potting soil and water. This way you are only planting the viable seeds and they sprout quicker due to the warmth of the fridge or mat. Put your potted sprout under your lights and you're good to go.

Don't give up, good luck and have fun!
posted by KathyK at 11:02 AM on December 13, 2007 [1 favorite]

It looks like it could be damping off, which happens when the seedling shrivels and rots right below the surface of the soil.

- Make sure that you are using sterile soil meant for seed starting. It looks like you are.
- Once a day might be too much - stick a fingertip into the soil and if it still feels moist, you don't need to water. Herbs like it a little one the dry side. Of course, when you are just starting seedlings you don't want them to dry out too much.
- You can get a shoplight fixture and a grow-light cheap - less than $20 for both. I used a shoplight fixture and a growlight to start seeds in my nearly windowless basement. It took a lot of trial and error.
- Parsley is really hard to grow from seeds. It germinates very inconsistently, taking anywhere from 3-6 weeks to do so. I always just buy a parsley plant every year instead of trying to grow it from seed. Also, it has a long tap root (it's in the carrot family) so you have to have a pretty deep pot for it. But it's not impossible - you might as well give it a try.
- Basil is very easy to grow from seed, as is cilantro and chives. Cilantro goes to seed pretty quickly, so you may want to stagger your plantings on that one, planting a few more seeds every couple of weeks so that you have a fresh supply.

Here is the key to growing seedlings indoors: You want to hang the grow light right over the sprouts - as close as you can get without touching the leaves! Seriously, maybe leave a half inch for airflow, but no more than that. You can put the pots of seedlings on top of something to raise them up closer to the grow light, too. Just as long as they're almost touching the light. Adjust as they grow.

You will probably end up with slightly leggy plants anyway. Harvesting your herbs on a regular basis will encourage bushiness. Once they are established, harvest your herbs by cutting right above a set of leaves. When it gets warm enough to set your plants outside, give them some real sunlight. They'll like that.

You should thin out your seedlings to 2-3 per pot, too.

Okay, I have rambled on far too long. Good luck! Growing herbs is very rewarding.
posted by Ostara at 2:13 PM on December 13, 2007

I must respectfully disagree with zaelic about the relative merits of grow fluorescents vs. standard fluorescents. The grow ones really do work better, and here's why.

All fluorescent lamps work by making low-pressure mercury vapor inside the tube emit ultraviolet light by running electricity through it. All tubes of a given size and wattage rating have pretty much exactly the same amount of ultraviolet light emitted internally.

To convert that ultraviolet ("black") light into something we can use, the inside of the lamp tube is coated with a mix of phosphors: substances that emit visible light when illuminated by ultraviolet. Different kinds of phosphor emit different colors of light, and the color balance of a given fluoro tube is determined solely by the proportions of these chosen for the tube coating.

In a normal tube, a fairly large proportion of green-emitting phosphors are included in the mix. In a grow tube, these are missing, and the only phosphors chosen are those that emit light that plants can use (reds and blues). That makes them look a bit dimmer than a standard tube to us, because we judge overall brightness based on the response of our "black and white" retinal light sensing cells, the rods, and these are most sensitive to green light.

But since the total light energy emitted by any tube of a given wattage rating will be the same, regardless of phosphor mix, it's perfectly clear that the green phosphors in a standard tube are just wasted space, and the green light they emit is just wasted energy, from the plant's point of view. You can get the same growth rates using two or three grow tubes as you would from four or five standard tubes of similar wattage.

You can actually get several kinds of grow tubes. Tubes optimized for the vegetative (leafy) stage of growth have mostly blue phosphor with a little bit of red; these are what you'd pick for growing leafy herbs. For flowering and fruiting (e.g. tomatoes) you'd get better results from the redder tubes optimized for that growth stage.

If you get serious about growing under lights, and you're considering employing more than about ten fluorescent tubes at 40W each, you should, as zaelic says, consider high-intensity discharge lamps instead. These give you about 50% more light for a given amount of electricity than fluorescent tubes do, though they run much hotter so you can't put them as close to the plants. This in turn means that you need to pay much more attention to reflectors than you would with fluoros; a typical indoor growing setup with HID lamps surrounds the whole growing area with flat white reflective panels.

Metal Halide HID lamps are good for vegetative growth, and Philips Son-T-Agro high pressure sodium lamps are the gold standard for flowering and fruiting. But really, for four little pots of assorted leafy herbs, all you need is three or four two-foot grow fluorescents. Your local pet shop might be a good place to pick these up, as they're commonly used over aquarium tanks to promote the growth of leafy water plants.
posted by flabdablet at 5:01 PM on December 13, 2007 [1 favorite]

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