When to bring your vegetables outside?
13.8 years ago garlic bulbs, onions, peppers, seeds, spinach, summer, tomato
Every time I have a discussion with a beginner gardener, this is the most common question. Typically the answer involves figuring out your last frost date then doing some backwards math when to start your seeds or purchase your plants from your local nursery. The problem with this is there is an assumption of the rate at which temperatures will increase after this no frost date. It doesn’t really matter how many weeks after the last frost when you bring out your tomatoes but the fact that it is over 65° F
This is good for estimation but ultimately it comes down to what temperatures various vegetables can survive and thrive at. This is ultimately when you should decide to start bringing those fragile plants outside. For reference the table below shows these temperatures for various vegetables.
Vegetables | Thriving Temp Range |
Surviving Temp Range |
Hot Vegetables eggplants, sweet potatoes, peppers, watermelons, okra, tomatoes |
70° F – 85° F 21° C – 30° C |
65° F – 90° F 18° C – 32° C |
Warm Vegetables beans, black-eyed peas, cucumbers, melons, sweet corn, squashes |
65° F – 75° F 18° C – 24° C |
50° F – 90° F 10° C – 32° C |
Cold/Warm Vegetables artichokes, beets, broccoli, brussel sprouts, cabbages, carrots, cauliflower, celery, chard, collards, endives, fava beans, fennel, kale, kohlrabi, lettuce, parsnips, peas, potatoes, radishes, rutabagas, spinach, turnips |
60° F – 65° F 16° C – 18° C |
40° F – 75° F 4° C – 24° C |
Cold Vegetables garlic, leeks, onions, shallots |
55° F – 75° F 13° C – 24° C |
45° F — 85° F 7° C – 30° C |
Now that you know what temperatures your veggies grow best in, unless you can find a news station with a 2-3 month forecast this doesn’t help you too much. Fortunately we have been saving weather data for some time now and with some simple statistics you can make a more logical prediction of when this may occur (compared to last freeze date)
One site that makes this very easy is WeatherSpark, it uses historical data with great visuals to easily determine when the best probability of picking the right date to plan on your veggies going out into the great unknown.
As you can see in my area we rarely stay in the thriving temperature zone during a 24 hour period which is the reason why I personally keep my tomatoes and peppers in my automated grow box as long as I can.
Hopefully WeatherSpark can give you some incites about predicting the best times to bring those veggies out for a successful crop this year.
Tags: seed, starting seedling
13.8 years ago
This is an awesome guide. Thanks!
13.8 years ago
I came across a chart on the website for a seed company that lets you plug in the average last date of frost for your area and it will give you when to plant seeds of different species:
http://www.johnnyseeds.com/e-PDGSeedStart.aspx??source=HomeSeedCalc0211
However, not all types of vegetables are listed. Does anyone know of a better online tool?
13.8 years ago
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13.8 years ago
Some of the crops you list are typically started from seed directly in the garden. You bring up a good point on the rise in temperatures (or lack thereof) as being as important as the last frost date. I would also like to add that the soil should be allowed to heat up for many of the direct seeded crops.
Thanks for the good information.
13.8 years ago
Thanks for the guide you gave here especially the table reference you made for the plants. It is really helpful. Again, thanks a lot!
13.8 years ago
I like using this when deciding a good time to start hardening off my plants.
13.8 years ago
Very handy chart to have. Most of the things on there I have started from seed, including corn, with varying degrees of success! I have moved to an area that has a significant difference between the day temperatures and the night temps. It can be 70 in the day and drop 40 degrees at night- so my greenhouse will come in handy here. Just one more thing I have to take into consideration… happy gardening.
13.8 years ago
Thanks for posting this. I’ve always grown indoors because I had no idea when I should plant my veggies outside. Indoor gardening is nice, but it seems like a waste of energy when it’s bright and sunny outside.
13.7 years ago
Just another thought about bringing plants outside. One more thing to consider when hardening off is wind. If you have not been exposing your seedlings to some kind of mechanical motion like a fan or even just running your hand over them, you may have plants which can’t tolerate the spring winds once outdoors. You need to toughen them up a bit!
13.7 years ago
I live in North Texas (8a) and am amazed that kale, chard, spinach, and the other greens I planted last September actually survived the brutal 9 degree temperatures we experienced this Winter. And with nothing but a thin row cover thrown over them.
So, I think we sometimes underestimate the resiliency of our plants.
I was counting on reworking those beds for my Spring veggies, but lo and behold the greens came back and are as bountiful now as they were all Fall. And we do love our greens, so I’m using other beds for my veggie seedlings, which have been under lights for the past couple of months. Just about have them all out and planted now.
Great site! I’m starting to chart my progress as well.
11.9 years ago
Hi,
I planted spinach, lettuce and rucola late summer 2012. Just early enough for the plants to have a couple of leaves each looking at the sun before fall and winter kicked in. I checked on them recently and are positive they will survive even though we have had snow and minus 15 C (59f).
I’m hoping the result will be very early greens this year.