Vegetable Grow Chart

The below is a chart of how and when to grow the most common vegetables.  This is a chart that I developed for myself to put into my Garden Binder as a quick reference guide.

I have included both minimum and optimum soil temperature for germination of seeds.  The minimum is the lowest temperature at which the seed will sprout but it often takes a very long time, sometimes as long as a month for some seeds.  The optimum temperature is the temperature at which the seed sprouts the fastest…often taking just 2-7 days depending on the seed.  The importance of soil temperature is often the most over looked aspect of gardening and the most common reason why seeds just will not grow.

Soil temperature is more important than air temperature when planting seeds or seedlings.  In the Spring, you can have a warm spell of temperatures in the 70’s while the soil temperature is still in the 40’s. Every vegetable has a preferred soil temperature for seeds or transplants. A soil thermometer is essential for determining the proper planting time. Planting too early, before the soil has had time to warm up, can lead to seed rot, slowed germination, poor growth and disease.

For example, cucumber seeds usually take less than a week to germinate in a soil of 70 degrees F. They could take two weeks at 60 degrees F.  Peas will germinate in temperatures as low as 35 degrees F but it will take at least 3-4 weeks, but you can soak the seeds in water for 24 hours indoors at a temperature around 80-85 degrees F to speed the germination process and then plant the soaked seeds outdoors…even if the soil is at only 40 degrees F the soaked pea seeds will more than likely be up in 10-14 days.  Tomato transplants need a soil temperature above 60 degrees F for growth. Setting pepper plants out before the soil temperature is 70 degrees F could stunt their growth for the entire growing season.

Correct temperature readings need to be observed on three consecutive mornings. Readings should be taken at a depth of 1 – 2 inches for seeds and 4 – 6 inches for transplants.

Crops that will germinate in the coolest soils (40 degrees) include arugula, fava beans, kale, lettuce, pac choi, parsnips, peas, radicchio, radish and spinach seed. As of right now, I have already planted all of this in my garden 😀

With a soil temperature above 50 degrees, Chinese cabbage, leeks, onions, Swiss chard, and turnips can be planted.

When the soil warms to 60 degrees, warm season and many cool season vegetables can be sown, including beans, beets, broccoli, Brussels sprouts, cabbage, carrots and cauliflower. But be forewarned – beans will not tolerate any frost and may have to be planted again if the temperature goes below freezing.

Wait until the soil warms to above 70 degrees to plant warm season vegetables including tomatoes, eggplants, peppers, cucumbers, squash, corn and melons. Tomatoes and peppers are slow-growing and often take at least 6 weeks to grow to the stage where you can plant them out in the garden.  At the other end of the spectrum squash, cucumbers and corn grow quickly and are easier to start outdoors from seed .

Fertilizing can be anything from a side dressing of compost or partially composted, mostly dry chicken or goat hay up to watering with a homemade compost tea or fish emulsion…it really depends on the feeding demands of the plant and the quality of the soil where I have placed it.

I live in hardiness zone 6A and we always get plenty of rain so, as long as the plants aren’t spaced too close together, I don’t usually have to worry about constant watering except for the plants that really love their water…like cucumbers or melons.  For some plants it is best to not water near the time of harvest, for example, potatoes will not be as tasty or store as well when watered near the time of harvest.

As for crop tenderness, generally those plants labeled as “hardy” can survive a  frost or two and even a freeze….those labeled as “very tender” get chills if you so much as whisper the word frost.   “Semi-hardy” can survive a light frost or two but don’t leave em’ out all winter and “tender” means that they almost always die with the first hard frost of the year.

PLANT	START INDOORS (#weeks before last spring frost)	START OUTDOORs (#weeks before or after last spring frost)	MINIMUM SOIL TEMP TO GERMINATE (optimum temp)	COLD HARDINESS	WHEN TO FERTILIZE	WHEN TO WATER
BEANS	–	Anytime after	55F (80F)	Tender	Setting pods	Regular, from start of pods to harvest
BEETS	–	4 before to 4 after	40F (80F)	Semi-hardy	Right before planting	Only during drought
BROCCOLI	6 weeks	4 before	40F (70F)	Hardy	3 weeks after transplant	Only during drought
BRUSSEL SPROUTS	6 weeks	–	40F (70F)	Hardy	3 weeks after transplant	At transplanting
CABBAGE	6 weeks	Anytime after	38F (80F)	Hardy	3 weeks after transplant	2-3 weeks before harvest
CARROTS	–	4-6 weeks before	40F (75F)	Semi-hardy	In the Fall for the Spring planting	Only during drought
CAULI-FLOWER	6-8 weeks	4 before	45F (80F)	Semi-hardy	3 weeks after transplant	Once, 3 weeks before harvest
CELERY	6-8 weeks	–	45F (70F)	Tender	At time of transplanting	Once a week
CORN	–	2 weeks after	50F (95F)	Tender	When 8-10 inches tall and when first silks appear	When cobs start to form
CUCUMBERS	2-4 weeks	1-2 weeks after	60F (95F)	Tender	1 week after flowers bloom and again 3 weeks later	Frequently, esp. when fruits form
LETTUCE	4 weeks	2 weeks before	40F (75F)	Semi-hardy	2-3 weeks after planting	Once a week
MELONS	2-3 weeks	2 weeks after	68F (85F)	Very tender	1 week after bloom, and again 3 weeks later	Once a week
ONION SETS	–	4 weeks before	35F (75F)	Hardy	When bulbs begin to swell and when plants are 1 ft. tall	Only during drought
PARSNIPS	–	2-4 weeks before	45F (75F)	Hardy	One year before planting	Only during drought
PEAS	–	4-6 weeks before	35F (85F)	Hardy	After heavy bloom and pods start to set	Regularly, from bloom to harvest
PEPPERS	8-10 weeks	–	60F (85F)	Very tender	After fruit begins to set	Once a week
POTATO SETS	–	4-6 weeks before	45F (70F)	Semi-hardy	At bloom time	Regularly once blooming begins
PUMPKINS	2-3 weeks	1 week after	60F (95F)	Tender	Just before vines start running, 1 foot tall	Only during drought
RADISHES	–	4-6 weeks before	40F (85F)	Hardy	Before planting	Once a week
SPINACH	–	4-6 weeks before	32F (75F)	Very hardy	When plants are 1/3 grown	Once a week
SUMMER SQUASH	2-3 weeks	1 week after	60F (95F)	Very tender	Just before vines start running, 1 foot tall	Only during drought
WINTER SQUASH	2-3 weeks	1 week after	60F (95F)	Tender	Just before vines start running, 1 foot tall	Only during drought
TOMATOES	4-6 weeks	–	60F (80F)	Tender	Two weeks before ripening and 2 weeks after first picking	Twice a week