Why are my thai peppers not growing & ripening at their full length?

May 10, 2009 1:58 PM

Why are my thai peppers (birds eye chilli) not fully growing out?

Photo #1 I've had this Thai Pepper tree for at least two years now, but for some reason, this year the peppers aren't growing to their full length. Photo #2 Not only am I unsure as to why, I haven't been able to find any usable information on the web.

I water the plant once a day, usually when the sun has gone down or isn't shining on them yet. I use Jobe Fertilizer Spikes, and they are siting in Miracle-Gro Soil.

Here's what the weather has been like for a while now: Weather Image. Am I not watering them enough? Not providing enough plant food? Should I not have used some plant food I found a while back that had some special formula for tomatoes (I thought it was a general purpose plant food with a hint of formula for tomatoes)?

Some of the peppers are growing out to their full length, but most aren't: Photo #3

Thanks for your time!

posted by jasmeet to Home & Garden (11 answers total)

Could it be a variety?
posted by furtive at 2:01 PM on May 10, 2009

Response by poster: I highly doubt it. I know for a fact that this is the 'Thai' Birds Eye Chili. The past few times they've grown fruit (the peppers) it's been a decent length.

I can't believe I'm admitting size matters.
posted by jasmeet at 2:11 PM on May 10, 2009

Best answer: I would doubt the "tomato" food would cause a problem (IANABotanist) since both tomatoes and chili peppers are in the family Solanaceae. It could be watering--is the soil in the pot bone-dry as far down as your finger can reach before you water it? Are the tender new shoots drooping before you water it? Once a day should be enough, though.

How long has it been since the plant has been repotted? It could be that the roots have filled the pot; if this is the case, you will need to gently tilt the plant out of its pot, tease out the roots, trim them back and repot. If you prune the roots, you may also want to prune the branches of the plant back a bit.

It could also be that the plethora of commercial fertilizers have left residues that have built up, in which case, you may need to repot with new soil. You may also want to look into adding organic compost (comes in bags just like potting soil) or composted manure (comes in the same form; doesn't stink once it's stirred in) to the potting soil, and fertilizing with seaweed- or fish-based fertilizers.

Beyond those two possibilities, your pepper plant could have gotten some blight or disease, which i know next to nothing about, or could be infested with some tiny sap-sucking critter, which you might need a magnifying glass to see. If you take a look and find the aforementioned critters, pyrethrum/rotinone sprays are pet- and people-safe.

good luck to you and your plant.
posted by miss patrish at 4:12 PM on May 10, 2009

Mine did this for the first crop of last season. I gave it plenty of manure-based fertiliser and the next lot of chillis were enormous.
posted by embrangled at 4:23 PM on May 10, 2009

Best answer: Mostly concur with miss patrish. Could be root bound. Solution: repot to a larger container. Could have salt (fertilizer) buildup. Solution: run a bunch of water through the root ball, then repot. You might be overwatering. Solution: check to see that soil is mostly dry before watering again. You might be overfertilizing. Solution: ease off on the plant spikes. Could be some obscure fungal disease. Solution: pretty drastic, you might end up having to dispose of the plant, waiting a few weeks, then start a new one, with new soil and a new container.

I've grown quite a few peppers including the Thai birds-eye. Peppers generally seem to like it sunny, warm and dry. Hope this helps.
posted by telstar at 5:39 PM on May 10, 2009

Pepper fruits won't form fully if it's too cold or too hot. I can't tell if these pictures are indoors or out, but if they are outdoors, it is definitely too cold at night- it needs to be consistently over 58 degrees at night. If you have hot, dry winds along with your daytime temps that can also prevent fruit development.

You're also overfertilizing them- lots of nitrogen is not appreciated by peppers, and can lead to a calcium deficiency, along with high salts (from overfertilization and/or poor drainage). Usually this manifests as blossom end rot. So if I were you, I'd remove the fertilizer spikes. I think weather is most likely the problem now, but you are running the risk of further problems with the fertilizer.
posted by oneirodynia at 9:19 PM on May 10, 2009 [1 favorite]

Response by poster: Gonna try and answer a couple of questions as best as I can:

"is the soil in the pot bone-dry as far down as your finger can reach before you water it?"

This is the first I'm hearing of the technique, so I couldn't tell you. Usually the surface of the soil is dry and I water them.

"How long has it been since the plant has been repotted?"

Hasn't been, since I removed it from it's original container. It's not in a pot, it's in a planter though it's not the only plant in there (new thai pepper plants growing, and some weird oak tree thing)

Couple of things I would like to try, and would love feedback on. Some steps I'm thinking of trying:

-Remove the plant from it's planter, trimming the roots (really rather not, but if it's for the best of the plant, I can do it) and plant it in this huge pot I found. I'm going to have to fill the bottom out with regular soil (it's a huge pot, all I have right now) and then add Miracle-Gro for the rest of the plants, hoping the nutrients from the soil will make it down to the not-so-nitrified soil.

-The weather has been in the 80F's during the daytime, and dropping to the 50F's at night. I used to have the plant in colder climates (Northern California), seemed to do ok anyway. But who knows, maybe it's not so resistant to colder temperatures (age?). Oh yeah, the plant is outside. Start bringing it inside during night?

-I try not to use too many of the plant spikes. Usually just one for that planter, wait a while, when I know it's gone, put in another. I think the last time I had plant spikes in it may have been, Feb or March, and I just put in a new one couple of days ago.

I have pretty much confused myself as to what to do next. Should I move it into bigger pot? Remove fertilizer spikes, bring it in at night? Trying not to get rid of the plant if I can, it was the last surviving member out of the 6 that I got as a gift once upon a time 2 years ago.

Thanks for all your responses, I look forward to reading other feedback you have!
posted by jasmeet at 12:04 AM on May 11, 2009

Best answer: There's absolutely no reason to trim the roots if you're planting it in a larger planter.

Don't use Miracle-Grow soil. Use good organic soil. You're overfertilizing already,and it's not good for peppers (or anything else). You can't control the nutrition if you're using soil filled with fertilizer. It's a gimmick Miracle Grow uses to sell junky soil. You also don't want to use the plant spikes constantly because there are seasonal cycles to nutrient uptake. You shorten the plant's life by feeding it all the time, and like I mentioned above, you run the risk of creating the situation for a very common calcium deficiency in peppers.

The best time to fertilize peppers is 10 days after flowering. You should be using a fertilizer that has a high potassium (K) ratio- something like N3-P1-K6 (or 6-2-12, 30-10-60. The ratios remain the same, the numbers reflect percentages of the nutrient on the fertilizer compared to inert materials. Higher percentages of nutrients should indicate the use of smaller amounts of fertilizer per application. It's not important to have higher numbers, just worry about the relative amounts of nutrients to one another). You also want to make sure there is calcium in your soil. This is a difficult nutrient to make available to plants, because it needs time to be broken down by soil organisms. Look for a bagged soil with dolomitic limestone if possible (it's also available by itself as a fertilizer), and do not fertilize constantly with nitrogen of any type because the calcium is not taken up by the plant if there is too much nitrogen available.

As far as temps go, shelter your pepper from dry winds. You can bring it inside at night if you want to avoid low nighttime temps, or you can allow it to respond to the natural temps in your environment, and flower and fruit when it wants to (best option). Cut off all the aborted peppers, slice down the side of the rootball to free pot bound roots, ideally repot in good soil in a pot that's 2-3 inches larger all around than the one it's in now. Fertilize carefully 10 days after flowering. Water using the finger technique- allow the top 2-3 inches of soil to dry between waterings.
posted by oneirodynia at 7:28 PM on May 11, 2009

Response by poster: Pardon my ignorance, but what makes soil organic? I want to be aware of what exactly organic soil is, before I walk out of a place with something that's just the same as Miracle Gro.
posted by jasmeet at 11:23 AM on May 12, 2009

Best answer: the bag organic fertilizer comes in will say "organic" on it--that's a big selling point. it often costs a bit more than regular potting soil and the bag itself is often green. if you can't find any officially organic potting mix, regular potting soil generally doesn't have fertilizer in it--you pay extra for that privilege! and bags with fertilizer included will be marked as such. i tend to mix my own potting blend with ten bags of topsoil, a bale of pro-mix, five bags of dehydrated manure and all the compost from my compost pile, but that requires a large flat area, a tarp, rakes and hoes and other implements of destruction, and lots of sweat and elbow grease, and is generally a big mess. you could probably cut the "recipe" down and mix it in a big plastic tub.

i also wanted to agree with oneirodynia that you don't have to prune the roots if the plant is going into a larger pot; that's just if you need to maintain pot size--like if you happen to have a bay tree that, if it gets any bigger, will not fit in the door in the fall . . .

one of the issues with fertilizers is that they are usually intended for 1) plants in the ground, where the chemicals have the chance to dissipate and the soil gets turned over naturally by earthworms, etc, and 2) annuals, which explode onto the scene for just one year, and if they burn themselves out in an orgasm of bloom and fruit, who cares? they're just going to end up in the compost in the fall anyway. fertilizing a potted perennial is a whole 'nother kettle of fish, and should be approached more cautiously, with an eye to the long road ahead.

happy repotting!
posted by miss patrish at 11:56 AM on May 12, 2009

oh, also wanted to say if you're interested in container gardening, you may want to pick up a book or two that walks you through do's and don'ts and gives you clever tips you would never have thought of--container gardening is something of a science (and maybe a bit of an art form, depending on what you're growing!), very different from growing in the ground, or even raised bed gardening. it's also become very popular in the last decade or so, so there's a lot written about it. i'm afraid i haven't investigated the literature too much--i'm going the raised bed route, myself, with only a couple potted plants. i would recommend any books organic gardening publishes--they've been doing this for decades; same with rodale press.

something you might also want to look in to is whether there's a . . . um, i don't know what to call it; an old feed-store-type place in your area, where the whole dimly-lit, barnlike interior smells of loam and cedar and dusting powders, and the racks are stuffed with fabulous garden gloves, grow lights, seeds from seven different companies, and odd bits of hardware that might be for tilling the soil or cleaning a horse's hoof or ridding the lawn of moles, and if you don't know, the gentleperson behind the counter can explain it to you and give an accurate review of its usefulness or lack thereof. these are places where the workers can give you solid advice on your latest garden project as they weigh out your birdseed into a recycled brown paper bag. here in st. louis, that place would be okay hatchery in kirkwood. they have been a great resource for me; see if there isn't something like that where you live.
posted by miss patrish at 12:24 PM on May 12, 2009