Most people assume that potatoes have to be planted early spring in order to get a harvest.
Though you can plant potatoes in early spring, but let me tell you that it is not a requirement unless when the season is less than 90 days where you really plan to plant potatoes as early as possible.
Growing season in your locality will have direct impact on your gardening. For instance, if you’re living in Michigan, you’ll have a decent growing season of 140 to 160 days.
So, if your region has 150 days of growing season, which is favorable for potato plants (more on this later in the article), then gardening experts recommend to plan two harvest.
One will be early harvest (Early Spring, March or April) and other planting after 30-40 days (June).
Don’t plant in July because you’ll expect the harvest in late November, which is not good for the crop.
If you didn’t miss the above highlighted lines, then you might now know when to plant potatoes.
However, spend few more minutes you’ll get complete detail about favorable climatic conditions, how increasing heat impact water schedule and how to protect your potato plant from early frost.
When Is It Too Late to Plant Potatoes?
To determine the best time to plant your second harvest potatoes, there are few things that you must consider like Climatic conditions (last frost date), potato variety and desired harvest.
Note: If the temperature of the soil is above 45F and the last frost date is more than 90 days, then I think you can start planting potatoes. Anyway, I strongly recommend you to read below listed requirements of potato plant. This will ensure that you plan your vegetable garden accordingly.
Also Read: Is it Good to Use Bone Meal for Potatoes
#1 Climatic Condition
Can you grow potatoes all year around?
Yes, if you’re able to protect potato plants from winter and other climatic conditions. You can grow potatoes all year around.
However, for best harvest you must choose to grow potatoes in growing season (March to June). In some states this growing conditions can be limited to less than 90 days.
Soil temperature must be above 50 F to 70 F to successfully grow potatoes in your garden.
- In below 40F temperature potatoes don’t sprout well.
- 45F to 50F is ideal temperature for faster healings of wounds on cut potatoes.
- Tuber formation occurs when the soil temperature is between 60F-70F.
- In temperature above 95F tubers will not grow.
#2 When it Will Frost?
Potato plants can’t tolerate frost. However, you can save them by using cloche or a row cover.
It is important that you know the first frost date in your region. Only then you can determine whether to go for planting or wait for next season.
For instance if you’re living in Dallas, Texas, then you may expect first fall frost after Nov 9, so chances of frost before this date is very less. You can accordingly plan for early potatoes or other variety depending on the growing season left with you.
You can check first frost date in your state by entering zipcode here.
Also Read: Do Potatoes Like Wood Ash?
#3 Potato Varieties
Time of maturity depends on the type of potato you choose. This plays vital role in determining when to plant your potato crop.
Though there are different varieties of potatoes, you can divide them in 3 broad types.
- Early season potatoes – maturity time is 60 to 80 days.
- Mid season potatoes – maturity time is 80 to 90 days.
- Late season potatoes – maturity time is 90 to 110 days.
You can plant all types (including early, mid and late season) in early spring (March). (1)
For second harvest or if you’re planning for harvest in Nov (before frost), then you can plant in June (late spring).
According to growing season available, you can choose the potato variety.
How to Protect Potato Plants from Cold?
This plant is a cool seasoned vegetable plant and can survive light frost.
In Southern regions with relatively mild winter, you can plant and expect good potato harvest.
However, you must make sure the temperature of soil isn’t getting below 40F. Else, your seed potatoes won’t sprout.
Wet soil in colder climates may result in decaying of seed potatoes.
Protect your potato plant from hard frost or freeze by shifting the plant container indoors or grow them in greenhouse.
A greenhouse will provide necessary environment for your potato plant to grow by raising temperature when needed.
Growing Potatoes in Summer Heat
As mentioned above, potato tubers don’t form when the temperatures reaches above 85F-90F.
A report backs this claim, saying with increasing temperatures small RNA blocks the formation of tubers. On this study, Scientist came-up with a variety of potatoes that are heat resistant. You can try few of them to check how it works in your region.
You can use mulch, greenhouse and water regularly to reduce the increasing heat.
Most gardeners prefer to grow potatoes in grow bags, this will ensure that your soil temperature isn’t too high.
How to Protect Potato Plants from Frost?
Potato plants can tolerate light frost, but hard frost will damage the upper part of the plant.
Though, roots can come-up with new plant but it will negatively impact your plant.
You can grow potatoes in greenhouse or arrange row covers to protect the plant from frost.
Electric heaters in greenhouse will ensure the temperature doesn’t go below 40F.
Growing Potatoes Tips
Soil, Water and Sunlight are three essential requirements to grow healthy potato plant.
Soil: Well drained soil with pH 5.0-5.5
Watering: Soil should be moist but not soggy, check for dryness with finger and water if needed.
Sunlight: Potato Plant need 4 to 6 hours of bright sunlight.
Temperature: Soil temperature should be between 45F to 55F. Below than 40F will not allow seed potato to sprout and above 80F will stop production of tubers.
- Potting mix should include sand, garden soil and compost.
- Most people prefer growing bags to plant potatoes. These growing bags will provide favorable conditions to save from extreme cold or extreme heat.
- Plant seed potatoes 14 inches apart. In a grow bag you can plant 5 seed potatoes.
- Most gardeners don’t slice the seed potatoes; you can sow the whole seed potato.
- Depending on the potato variety, you can expect harvest in 80-140 days.
- You can regularly add a layer of garden soil and manure as the plant grows.
- Mulching around the potato plant will protect it from soaring heat and locks moisture for longer time.
- Though potato plants can survive light frost, the plant can’t tolerate hard frost. Use row covers to protect from frost.
You can plan potato crop twice if you’ve growing season more than 140 days. First harvest will be in March and the harvest will be in September. Second harvest you can start in June, November (before frost) will be your harvest month.
However, if your region has very less growing season then you must start with early season potatoes to save your crop from frost.
Never plant in Late July or August, else your crop can be damaged due to hard frost in late November.
I hope, now you know when is it too late to plant potatoes.