I’m getting questions on when things can be planted outside and I know some of you are from other parts of the country so rather than post this in timeline format I’m posting by soil temperature. I know you can buy special soil thermometers but you can also use a digital meat thermometer and call it good. Just clean it well before you stick it in your roast next.
These temperatures are the minimum soil temperature the plants require for germination and I’m lumping them in groups.
When the soil is 32 degrees Fahrenheit (if workable) plant these:
- lettuce
- onions
- parsnips
- spinach
When the soil is 40 degrees Fahrenheit plant these:
- beets
- broccoli
- cabbage
- carrots
- celery
- chard
- parsley
- peas
- radishes
- turnips
When the soil is 50 degrees Fahrenheit plant these:
- corn
- tomatoes* (I will cheat on this with black plastic to warm the soil and a hoop house so these I’ll start sooner since our summers are so short)
When the soil is 60 degrees Fahrenheit plant these:
- beans
- cucumbers*
- melons*
- peppers*
- squash*
*All these things are suited to warmer climes so I will be starting the seeds indoors long before the soil reaches these temps. After hardening off for 1-2 weeks I will plant these out when the soil reaches the right temperature. If you put the plants into soil cooler than they enjoy they won’t really grow anyway, hence the black plastic & hoop house.
Thanks for this!! My friend and I just got a plot at an urban garden.
GillieBean – that is so exciting! Would you consider doing a guest post about gardening in a plot? That is the only possibility for so many and I’ve never done it. It will be interesting to see how plots where you live compare with plots here in Seattle too.
I did some seed starting today myself. The season is already upon us!
Just thought I’d mention that often greenhouses have seed starting schedules appropriate for their climate. I often get asked when to start what, so I keep a few extras on hand to pass out each spring.
Emily – that is a great suggestion. I never would have thought of that but of course they would know.
Sandy – I have high hopes for spring crops this year. Watch we’ll have cloudy cool summer though and no melons or tomatoes.
Thanks for these temps! I’ve been looking at my meat thermometer, wondering if I could just stick it in the dirt. Guess I can!
Myrnie – it will be accurate enough. The Indians used to say it was time to plant beans when they could sit comfortably on the ground with bare bottoms. I’m guessing your meat thermometer is more accurate than that. :p
I was out with my trusty soil thermometer yesterday – checking to see if a bed under a cover was ready for spinach to be planted. I have a one page recap of the min-max and optimal germination temps for seeds that I use to judge if soil is ready to be planted with a specific crop. While spinach will germinate at 32 degrees – it will take a very long time for the seeds to germinate and emerge – whereas they will germinate in 7 to 12 days if the soil temp is 45 to 50 degrees.
Here’s a similar recap that shows the same basic info that you might find useful.
http://www.gardeners.com/When-to-Plant/warmenuflp,default,pg.html
KFG – that is helpful. I didn’t realize you were supposed to wait a little longer to plant pumpkins. I’ve always started them when I do the other squash. Maybe that explains why mine were ready in September last year although I just chalked it up to the crazy sunny weather we had.
Took 4 years off from gardening…just getting back into it.
And I scored a free recycled 12′x8′x10″ high at peak greenhouse. It’s only missing 3 double wall polycarbonate panels.
I had to spend a day disassembling it and loading it into my Explorer in sections.
I will be reassembling it in August.
I need the replacement panels, some vent hinges, and a couple of 55 gallon drums or plastic barrels for heat sinks, and some good ideas for how to lay out the inside for best usage.
Any ideas on layout and where to get replacement double wall polycarbonate panels locally?
I have a South facing back yard (where the garden is).
Yardworko I’m envious of your greenhouse. I don’t know anything about them though – I just plant cold-tolerant crops instead. Good luck! I know Sandy of http://10yearchallenge.com/ is putting her large greenhouse to good use and might be a better source for ideas for you.