Background: I sowed my first batch of tomatoes on April 4th on those transparent 12-grid trays w/ domes that are supes trendy right now, potted them up on May 4th & 5th into 3-inch transparent pots (which I now understand may not provide the ideal darkness for their roots, live and learn), and I would like to transplant them outdoors soon.
Questions: One concern that I have (and I’m not sure how concerned I should be) is potentially introducing outdoor wildlife into my indoor environment during the hardening off phase.
- Do other gardeners worry about this or am I over thinking it? Is it basically set them on a table (not on the ground), don’t leave them out there for too long, and hope for the best?
- What other steps can I take to keep my indoor environment as sterile as possible while hardening off some plants when they’re ready?
ETA Additional Reading: Hardening Off Seedlings: How to Safely Transition Indoor Plants Outdoors
Yes. I quarantine and observe for pests. I do the same thing when I bring new plants home. If the plants aren’t going to be a permanent residents I never let them near my permanent indoor plants. I don’t worry about things bigger then plant pest (insects/animals/ect) because either the hitchhiker won’t survive indoors or it’ll be something noticeable that I can catch and take back outside. The things capable of survival In a house already live here, the things that can’t won’t live long because the environment is actually quite hostile to them.
I don’t worry about this, because I live in a century home that’s basically porous to small outdoor critters already.
My 60yo trailer has the same problem. I’ve got box elder bugs for days, but my friends the house spider, the cobweb spider, and the jumping spider eat well and do their part. There’s a spider in every corner of my shower. Possibly perverts but they’re not weird about it. We’ve had a local rat boom for the past few years, but the dogs have been diligent. It’s the sugar ants that are the real motherfuckers.
My general approach is that my young seedlings live in one room until its time to harden them. Once they’ve left the nursery room, they dont go back there, so there’s no chance of transferring a pest.
In terms of other critters, most outdoor stuff doesnt want to be indoors. I’d be more concerned about bringing a foreign object from inside someone else’s house into mine than from outside inside.
Yes I’ve found it to be a problem in previous years when bringing things back inside after the summer. I think this year I’ll just be giving everything a preemptive spray with soap when I bring it in.
Thanks for chiming in, although I think we’ve got our wires crossed. I’m asking about protecting my indoor environment from plants that have been outside for an hour or two during the hardening off phase in the spring, before transplanting them into the ground. I agree about washing stuff before bringing it inside at the end of summer, that is a good idea.
I don’t really worry about this because I don’t bring my plants back inside when hardening them. I start seedlings inside under a light. Once they are big enough, I move them outside to a semi sheltered area, usually under the edge of the roof and out of the sun during the hottest parts of the day. When they have a few sets of leaves or the roots start showing at the bottom of the pot, I put them in the ground. After they go into the ground, they are on their own to live or die.
I live in a very mild climate and, with exception to harsh midday sun, I don’t have to harden the seedlings much. Aphids are a serious problem and I don’t want them in my aerogardens inside.
During the hardening process between seedlings and planting, no.
If I use dirt from outside, yes. Buy a large disposable aluminum baking dish and just slow bake it to kill off potential gnats and such.
No mice ever, thus far, if that’s what you’re asking.
I’m less concerned about mice and more concerned about for example flies and other winged insects landing on my tomato plants during the few hours that they’re outside, laying eggs, making themselves at home, and then spreading to my other indoor plants when I bring the tomatoes that aren’t fully hardened off yet back indoors, potentially causing an infestation among my indoor plants. I feel like I am being overly paranoid, but I hope this helps clarify the scenario that I’m asking about.
Had some chilli’s in over winter. Had what we think was fruit flies all over the house. Quite annoying. Relieved to get them back out in spring.
Next time that happens, look into nematodes. Eliminates the issue in a weeks time and keep living on the soil, reducing the chance for it to be an issue again.
I use a cold frame to deal with this, once they are outside they stay outside.
I see, so you just open up the cold frame for a few hours a day until they’re ready for full time?
Keep it open for airflow and to keep temps down during the day, and close it at night to keep the heat in and protect from the frost. Also keeps rain and snow off as well.

The top opens as well.
Not really. They’re not out there long enough to be a major risk. The easiest thing you can do is keep them separated from other plants when you bring them back inside.
I have a feeling this is the approach I’ll be taking, I just need to set up a separate area for them before they go outside for the first time.




