I kill baby plants!

May 17, 2007 7:54 PM

I kill baby plants! Help me, gardeners!

So my problem is that I am unable to grow things from seed.

I do not, exactly, have a black thumb. Things I buy as plants grow vigorously, by and large. Also, I've read up on this problem, but all the gardening experts seem to think that seed-starting is incredibly easy, and don't give tips for MORONS such as myself.

When I grow things from seed, this is how it goes:

I plant the seeds in some variety of (sterile) starter mix or potting soil or those little discs that expand alarmingly when watered. I use new or clean pots. I plant the seeds at the recommended depth. I water thoroughly.

I put the pot/tray on my kitchen windowsill, which gets a reasonable, but not overwhelming, amount of light.

"Grow, grow, baby plants! " I say.

After a few days, the seeds sprout and grow! I cheer. But then, tragedy strikes. At about three, four days to a week post-sprout, the seedlings seem to stop growing.

The seedlings start to look sad. Not sick, mind you. Just... a general failure to thrive. They don't have bugs or look diseased or anything, they just stop growing. I nurse them along for another week or two with flagging hope.

Then I give up and buy generic tomato plants from the hardware store.

I want to be able to grow interesting things from seed! What am I doing wrong?

I realize that you're supposed to harden seedlings off, but surely not at four days? Am I overwatering? Are they not getting enough light? Am I planting the seeds too close together? The seedlings start to look depressed before they've gotten their first real leaf; should I be thinning right away? Should I maybe put them outside as soon as they sprout?

HELP. The only tomatoes I'm able to grow from seed are the vigorous plum tomatoes that volunteer themselves in the compost, which is totally unintentional and, frankly, kind of humiliating.

Any clear instructions on how to start plants from seed? A book or website would be very pleasing, too.

If it matters, I live in zone 10. (But the plantlets expire long before going outside. ARGH.)

posted by thehmsbeagle to home & garden (11 comments total)

Sounds like damping off, which is a blanket term for several types of fungal infection. Uber-clean (sterilized) soil and pots are the preventative, fungicides can be the cure. Detailed info at the link.
posted by jamaro at 8:13 PM on May 17, 2007

You're probably overwatering. The seedlings can't get too much light, but if you don't let the soil dry out between waterings you'll probably kill them. I like The Cubed Foot Gardener for information on starting seeds and general gardening.
posted by electroboy at 10:10 PM on May 17, 2007

Do you cover the pots/trays at first? I'm not sure what sort of difference it makes, but all instructions I've seen say to cover the container with clear plastic (cling-wrap works) to retain moisture. Of course, I take it off after the seeds sprout (sometimes waiting until they reach the plastic), and yours are doing that without trouble - but maybe it helps with early root growth?

I've noticed that my seedlings respond to the condition of their roots a lot. I had some seedlings (pepper and basil) that I started in those magic expanding peat discs. I moved some to larger pots w/ soil (still in the discs, but now with delicious dirt surrounding them) and left the rest in their discs in the tray. The ones in the pots immediately started growing like crazy, while those still in the discs have stayed much smaller.

Not sure if that helps, but I can at least answer several of your questions based on my experience:

I realize that you're supposed to harden seedlings off, but surely not at four days? Should I maybe put them outside as soon as they sprout?

Nope. Plants can grow indoors. I have grown several plants (mainly herbs) from seed indoors. I don't think that would cause them to fail so early.

Am I overwatering?

Yeah, you might be overwatering. As with any other watering, I'd err on the side of dryness. I recently had some extra basil seedlings dry up and fall over, but they picked themselves back up once watered. So it takes a lot to kill them by drought.

Am I planting the seeds too close together? The seedlings start to look depressed before they've gotten their first real leaf; should I be thinning right away?

Doubtful. I have plenty of crowded seedlings that make it to their real leaves (then I'll thin or transplant).
posted by whatnotever at 10:16 PM on May 17, 2007

When that happens to me, I plant many times as many seeds as I need to, then Try Things.

Some get more water.

Some get less water.

Some get more light.

Some get more warmth.

Some get companion plants.

Some go outside.

Some go in the humidicrib.

Some get planted further apart.

Some get planted closer together.

Some get put out earlier.

Some get to spend longer inside.

Some get stronger fertilizer.

Some get weaker fertilizer.

Some get no fertilizer.

But all of them get just one thing changed from what I was doing.

Figuring out what's best for next time doesn't usually take more than two rounds of this.
posted by flabdablet at 10:18 PM on May 17, 2007

Am I overwatering?

Thirded, unless you respond otherwise. Wait until soil is dry to the touch before watering, and even then no need to soak a pot when you've just got a little seedling. A little goes a long way.
posted by poppo at 2:47 AM on May 18, 2007

I think tomatoes are kind of hard to grow from seed. Try something easier, like radishes!
posted by footnote at 6:57 AM on May 18, 2007

This is my first year of starting seeds indoors and through some divine intervention, I’ve managed to be successful. Here’s a pic of all the plants I was able to start from seed. There’s broccoli, Brussels sprouts, cauliflower, green pepper, parsley, zucchini, cucumbers, squash, tomatoes and a slew of flowers.

I live in Zone 5 and have an average frost free date of May 6, however, I’m waiting until next weekend to put out my plants. I started sowing my seeds in mid-March. You will want to check your USDA Plant Hardiness Zone and the corresponding frost-free date. Since you are in Zone 10 your average last frost free date is January 30 and your first frost is November/December. That’s a really nice, long growing season right there. You may want to double-check with a horticulturalist at a reputable garden centre to understand the recent trends in weather the last couple of years. Some years are cooler than others.

Once you know your average last frost-free date, use this excellent seeding chart called the Lazy Gardener’s Automatic Seed Starting Chart. It’s great and what I’ve been using.

Start off with clean pots, a good soiless mix (potting mix is too heavy for little seedlings) and some fresh seeds. You’ll know the seeds are fresh if they have this year’s date on it. Older seeds may not have been stored properly and may have a lower germination rate.

Seeds need heat to germinate, so once you’ve sown them into those little Jiffy peat pellets (the ones that expand with water) then you should put the tray into a sealed bag or covered with a clear dome and put it on top of a warm area, usually your fridge. This will help the seeds germinate quicker. Most seeds have an optimum germinating temperature of 70°F. You may want to buy a heating pad if you don’t have a suitable warm spot. Once they’ve sprouted, take them out of the plastic bag/dome and put them by your windowsill.

You can also try pre-sprouting them using a coffee filter and a Ziploc bag. I’ve done this with my zucchini, sunflower and cucumber seeds and it works great. Cut the coffee filter in half (less waste), fold in half and dip in water. Unfold the filter, place your seeds on one side and fold it back up. Put in the Ziploc bag and label. Place on a heated surface like a heat pad or on top of your fridge. Check everyday to see if the seeds have sprouted. Make sure the coffee filter hasn’t dried out. Once they sprout, you can put them into your Jiffy pellets and put them on the windowsill.

Make sure they get lots of light or they’ll get leggy trying to stretch towards the sun.

Now, for your questions:

I realize that you're supposed to harden seedlings off, but surely not at four days?
Hardening seedlings doesn’t start to happen until you get closer to your planting date, usually one to two weeks before you plant them out, roughly two months after you’ve started indoors. So, no, you don’t harden off after four days.

Am I overwatering?
The description of your seedlings sounds like you are overwatering them. If they’re on a windowsill they won’t be able to dry out quickly enough before you think you need to water them again, which may cause the seedlings to “damp off”. Try to keep the seedlings moist, not wet. Also don’t water your seedlings from above. You should add water to the bottom of the tray, let the soil in the seedling tray soak up the water for about 20 minutes and remove any excess water from the bottom. This way you aren’t disturbing the surface of the soil or damaging the stem of the seedling. If you stick your finger in the soil and it’s mushy, then you’ve put too much water in. If your finger comes out with little bits of soil on it, your soil has enough water and you should wait until it has dried out (a little bit!) before you water more. Don’t let the soil get dry at the edges of the tray.

Are they not getting enough light?
You said that you put your trays on a windowsill. If that’s all you have, a south-facing window is best. However, you may want to consider setting up a fluorescent lighting area to put your newly sprouted seedlings. I put together my grow-op with four sets of shop lights and two different kinds of bulbs. You can see the set-up and the details here (self-link). Depending on how many seeds you want to start, you’ll probably only need one light.

Am I planting the seeds too close together?
Depending on the size of the seed, I would only sow one or two seeds per Jiffy pellet, spaced 1/8” or ¼” apart. Small seeds like green pepper and tomato I would sow one to two seeds per pellet and one seed per pellet for larger seeds like squash. As the seeds germinate you may have one or both seeds sprout. If both seeds sprout, keep the larger, stronger sprout and snip the stem of the weaker sprout with a pair of scissors. Don’t try and pull the sprout out, as it will damage the root of the stronger one.

The seedlings start to look depressed before they've gotten their first real leaf; should I be thinning right away?
Thin seedlings to one seedling per pellet.

Should I maybe put them outside as soon as they sprout?
No, seedlings need warmth to grow and will be stunted in cold air.

Any clear instructions on how to start plants from seed?
Here’s a couple of really detailed articles that I found helpful:

Sowing Seeds: How, When and Where to Sow Your Seeds
A Prescription for Cabin Fever: Start Seeds Indoors

Seed Sowing and Saving is an excellent book for beginners. I bought this after I had sown all my seeds as I’m now interested in how to save them and I regret not buying it sooner. It would have cleared up many of my questions when I was first starting.

A couple of good forums:
GardenWeb: Growing From Seed and also their FAQ page
You Grow Girl: Seeds, Seed Starting & Growing forum

Have fun! The coolest part is watching seeds grow from a tiny seed into a towering plant. Seeds do well in the right setting. I was pretty nervous when I started but as long as I gave them the right amount of light, heat and water they did pretty well. Email is in my profile if you have anymore questions.
posted by KathyK at 8:08 AM on May 18, 2007 [50 favorites]

Thanks, everyone! I think I must indeed be overwatering the poor things.
posted by thehmsbeagle at 9:30 AM on May 18, 2007

I put my seeds in a wet paper towel and put that folded damp paper towel with the seeds inside, inside of a zip-lock baggie, place that in a warm dark place, I like using the water heater closet in my home. They germinate very well. Also, get them in the ground as fast a possible and do NOT overwater.

Also... always thin your sprouts, take the weakest ones out and leave only the biggest, strongest.

They are like little human bodies, they need rest in-between growings cycles. I grow a lot of different plants at different times of the year. My wife says I have a green thumb, she on the other hand, can kill a Boston Fern. She even killed her "lucky japanese/chinese bamboo plant that we gave her!
posted by winks007 at 1:53 PM on May 18, 2007

I've been an Organic gardener for about 20 years and while I agree the problem is probably sterilization and saturation related, there may be other approaches. First, there is nothing humiliating about either buying tomatoes or moving volunteers. Remember that the volunteer germinated under local, natural conditions. Seems that's a trait worth selecting for. This can make my garden seem disorganized but it also tests various co-growing options as they tend to show up spontaneously. I have several plants that I encourage as volunteers or select for. Tomatoes are one of those.

If you are determined to start indoors from seed. Keep them warm, tray warmer or some such. Use artificial light to prevent them from getting too leggy. Make sure everything is sterile. Don't start them too soon.
posted by Toekneesan at 2:58 PM on May 18, 2007

"I put the pot/tray on my kitchen windowsill, which gets a reasonable, but not overwhelming, amount of light."

Sure, don't overwater them, but mainly give them more light. A shop light with full spectrum tubes is good. So is putting them out in the sun during the day and bringing them in at night. The former is lazier, once it's set up. The latter is better light.

Tomato seeds are super easy to start. Also, they last almost forever (5 years+), even without being kept in the freezer.

You harden them off a few days or a week before you are ready to plant.

Nth-ing Gardenweb.
posted by Listener at 6:22 PM on May 21, 2007 [1 favorite]