Starting Seeds In Cheap Lowes Greenhouse

[invisiblegirl76]

Hello. I started some herb seeds in one of these metal greenhouses (https://www.lowes.com/pd_404388-15564-44 ... 24343&pl=1) that I bought from Lowes. It's metal shelving with a plastic bag over it that you unzip and zip up. I've been watering every day, but nothing has come up. It has been 2 weeks now.

Do you think it's too hot in there for the seeds? We've been having a sunny February, and the greenhouse seems to get around 100 degrees during the day. I'm not sure what it gets down to at night, but we haven't been having any frost, so it seems like it should work. I'm wondering if I should try again or give up on it. What do you guys think of these things?

[NJ Bob]

For starters, where do you live and what are you growing?

[Allyn]

If the temperature gets too hot, it can kill the seeds. I'm sure other folks will be along with more expertise, but I would get a min-max thermometer so you know what's going on inside the tent.

What zone are you in?

[invisiblegirl76]

I live in Northern California, zone 9. I planted parsley, basil, and cilantro.

[jal_ut]

I don't know what to suggest on the herbs. Where did you get the seeds?
Make sure to plant fresh seeds meant for planting. Old seed or seed that
has not been properly stored may not be viable.
Try some tomatoes and peppers?

[rainbowgardener]

I am starting seeds in one just like that, but mine is in my unheated garage, with lights hung over the shelves.

Absolutely you need a min-max thermometer. They are not expensive. I have one in mine. If yours is outside in sunshine, and you didn't open it up, you probably cooked your seeds.

Last night it got down to freezing where I am. With no heat source except the lights and a heat mat under two of the trays, it stayed no colder than 55 inside the greenhouse.

I have been unzipping mine in the daytime. When it is warm enough, I open it all the way up--roll the front flap up. Zip it back at night.

I also found that it gets VERY humid- wet inside. Every AM when I open it up, I shake a bunch of water off the front flap and wipe a lot of excess water off of everything inside.

Parsley and cilantro can be slow sprouting, but definitely your basil should have been up a week or more ago. I doubt it will still sprout now.

[imafan26]

Basil should come up fast. Parsley and cilantro can take a while especially if you did not soak the seeds first. They are not easy beginner seeds. They are also cool season plants that probably do not like getting up to 100 inside the tent.

Is this greenhouse indoors or out? If it is ouside and the temperatures are mild you probably don't have to keep it zipped up all of the time.

If you are keeping things zipped up there won't be much air circulationa and the pots will dry slower. You should water as needed. Seedlings like to be moist but not soggy.

A thermometer will really help. If your daytime temps are over 60 degrees you probably can leave the unit open during the day. I would only enclose it at night if it gets below 50 degrees. Water as needed. If the pots are still very moist they can go another day. Seedlings don't like to dry out but will dampen off if it is too soggy.

Try the seeds again. Premoisten the soil so it is friable but not soggy. Soak parsley and cilantro seeds overnight to speed germination. I plant seeds shallowly as they need light to germinate. Parsley and cilantro take longer to germinate 2-4 weeks. Mine will usually germinate within two weeks and sometimes sooner, but I have figured out what they like and don't have problems germinating them.

[Susan W]

I'll weigh in with my 2c or 2 seeds. I use the mini greenhouses on the deck, against house, south face, for plant starts. For seed starting stay inside, with more even temp control. The GH does heat up, fast. If sunny and only 45 out, may heat up to 80+ by late AM.

You're trying parsley, basil and cilantro? Cilantro is a cool season plant, and if your summers are hot, will go south in June or so. I don't soak the seeds prior to planting, and the parsley is up in 5 -7 days. Then takes forever and then some to get to usable size! I do use the jiffy peat pellets in small 10 or 12 per tray. When planting, get them to puff up and get thoroughly wet with warm water.

[invisiblegirl76]

Thanks for all the comments! Lots of good tips on here. I live in Petaluma, near San Francisco. We're having a very warm February--it's getting into the 60s and 70s during the day, high-40s and 50s at night, no frost that I've noticed. The greenhouse is outside and gets full sun all day. I forgot to mention I also tried butterfly bush seeds (completely new to me) and chamomile. Nothing came up, so I think it got too hot in there and cooked the seeds. I noticed that an onion plant was trying to grow in the ground under the greenhouse and the ends turned brown, like they cooked.

I'll get a thermometer and try again. Can you give me an idea of what temperatures I should be shooting for inside the greenhouse? What is too hot and too cold, generally speaking, for seeds?

[rainbowgardener]

what is too hot or too cold varies considerably by type of seed. Parsley seed needs to be soaked overnight first and germinates best at temps between 80-85. But note for many of these seeds, germination temperature is different from the temperature the seedlings like once they are growing. Parsley actually likes cool weather better and will grow better with temperatures around 50. It can handle temperatures down around 40 or even less once it is a sturdy little plant, well established and hardened off (gradually acclimatized to lower temperatures). Temperatures that plants can handle when hardened will kill them in a sudden drop.

Yes, I think your seeds were probably cooked. If you had your greenhouse in full sun, zipped up, it probably got well above 100 in there. It's called the "greenhouse effect" and it is what is doing our planet in. Very powerful.

Cilantro germinates best at temperatures from 55 to 70. The seeds need light to germinate, so do not cover them, just press them down lightly so they are in good contact with the potting mix. Cilantro is also a cool weather plant that fizzles as soon as it gets hot. It can stand temperatures down to freezing, once germinated and hardened.

You can look up for each seed the conditions it needs. I deal with having seeds that need heat and seeds that don't all in the same little greenhouse by having some on a heat mat and some not.

Here's a thread we had on seed starting basics: https://www.helpfulgardener.com/forum/vi ... 48&t=44183

[Meatburner]

invisiblegirl76, I have been using one of those for the last 4 years but only inside for seed starting with four 24" florescent fixtures. The cover remains on with the front open and a fan blowing over the plants. They are worthless outside, in our climate anyway, as the sun will destroy the cover very quickly and any amount of wind will twist it into a mangled heap and it is next to impossible to regulate the temperatures inside. It does work great indoors for me. I actually just picked up another one so I can leave the old frame outside for hardening off seedlings and then use it for potted plants.