indoor green house with insects

Asked April 10, 2020, 5:07 PM EDT

Hi - I just started to grow some seeds indoors. I recycled those little berry containers and make them my mini greenhouses. The seeds were able to sprout but i also started to get some gnats. Is that ok? I try to partially open the covers during the day so the humidity inside is not too much but it still generating some gnats. What should I do about them? Thanks.

Hennepin County Minnesota

7 Responses

They are probably fungus gnats. They feed on decaying matter in the soil. Did you use fresh new potting mix? They like damp places and soil. If the plants have their first set of leaves take the lids off and leave them off. Let the soil dry out before watering again. You don't want the seedlings to wilt but you don't want them to be wet all the time. You can buy some yellow sticky traps that the gnats are attracted to and get suck on to get rid of them.

Thanks for the info. I sectioned the container and put different seeds in different sections. Some have sprouted some had not. Is it okay to just leave the lid off and keep spraying the areas where there are no sprouts yet? will the gnats harm the plant? If not, i am okay with just the annoyance.

Sure that is fine. That way the ones that have sprouted won't damp off. The gnats won't bother the seedlings. They can be annoying though so you still might want to try to get rid of them. Here is a link to info about them. https://extension.umn.edu/product-and-houseplant-pests/fungus-gnats

Thanks for the advice again. The plants are growing well.

Now that it is starting to warm up around high of 60s during the day but high 30s at night. Will it be okay for the plants to be taken outside 24/7? Or at what temp at night when I can leave the plants all the time?

I have some arugula. When can I start to harvest from it?

BTW, here's some pictures of my plants - first pic. Second is the arugula on the center left.

You need to transplant things into individual containers before they get much larger. It all depends on what it is and whether they are cool season plants or not. Lettuce, onions, broccoli, cabbage and cauliflower are all cool season crops that will tolerate a frost once they are hardened off. Tomatoes, peppers, cucumbers and melons are all warm season crops that do not like the cold so they can't go into the garden until there is no danger of frost anymore. You can set things outside during the day and bring them in at night. Here is a link to info that should be helpful. The arugula can be harvested when it gets a little bigger. You need to get the tomatoes out of there and into individual pots right away. https://extension.umn.edu/find-plants/vegetables

Thanks again. I've transplanted the tomatoes and some other plants. It looks like the temp are going to stay in the low 40s overnight now. Can I leave them 24/7 now if temp does not drop below 32F or are the little plants will still be in danger with low 40s temp?

No tomatoes do not like cold temps. The cool season plants yes but tomatoes and peppers, no.