The earliest green beans should be planted is when all threat of frost is over and the soil temperature averages 60 degrees or more. The latest green beans should be planted is when the variety being grown has enough time to reach maturity before the first expected frost.
Green beans are sensitive to cold and should be planted when all threat of frost is gone. The seeds will not germinate if the soil is too cold so measuring soil temperature is the best way to know it’s bean planting time. If planting later in the season you need to give the plant 10-12 weeks before the first expected frost or check the specific variety you’re growing for a more exact time to maturity.
To measure the soil you can use a meat thermometer if the gauge reads low enough or a soil thermometer. The soil thermometer looks just like a meat thermometer but the gauge reads down to 0 degrees. It’s ideal to check the soil between 9-11 AM to get a good average. This is when the soil has warmed up a little from the night but has not been inflated from the afternoon sun. Just stick the thermometer in the ground for 5 minutes and we are looking for at least 60 degrees.
Jim Myers of Oregon State University horticulture program says that beans will germinate at 50 degrees but that there is a high chance of the bean cracking and microbes getting into the bean creating rot and bad germination rates. He also says that white colored beans have a higher chance of cracking and if you’re going to plant beans with soil temperatures between 50-60 degrees to try and use dark colored beans.
Best Time to Plant Green Beans
The best time to plant green beans is when soil temperatures are at least 60 degrees and with air temperatures between 60-85 degrees. If you live in a hot area you want the fruiting stage to occur when temperatures are not regularly above 85 degrees. Green beans flowering in hot temperatures of 85 degrees or above may fail to produce pods.
Starting Green Beans Indoors
Starting green beans indoors can give you a head start to the season and allow you to get fresh green beans from the garden a few weeks earlier than you would planting seed directly into the ground. Green beans have roots that are susceptible to transplant shock so it’s important to use a medium that you can transplant the whole block into the ground.
Cow pots are what I recommend. They are starter pots made out of cow manure that allow roots to freely grow through them and add some nutrients right next to the young root systems. They are made by a third generation American dairy farmer and are completely sterile and stink free.
Can I Plant Green Beans In July
Yes in almost any area July is a great time to plant green beans. The soil is warm making for quick germination. Hot temperatures and full sun will lead to strong vegetative growth in the first month and a half of the plants life. By the time flowering and fruit production start temperatures will be more temperate. This is good because high temperatures regularly over 85 degrees during flowering can cause little or no fruit production.
Growing Green Beans From Seed
You can check the viability of your bean seeds before planting if you want. Take 6 paper towels and wet them with warm water and then wring them out so they are moist. Place the seeds in between the paper towels 3 on each side. Then place the paper towels with the seeds in it in a sealed ziploc bag. Keep the bag in a warm area at least 70 degrees. Check on the paper towels and drip water on them to keep them moist if they dry out. In 2-3 days you should see sprouts coming from the beans.
To grow green beans from seed just plant the seed directly into the dirt. Bean seeds will germinate with soil temperatures 60 degrees or above. The warmer the soil the quicker the beans will germinate, the cooler the soil the slower the germination. Expect to see little bean plants in 4 days – 2 weeks.
How to Plant Green Beans
Take a tool and make a straight line in the dirt. For pole beans use a finger and make a hole 1 inch deep every three inches. For bush beans make a hole 1 inch deep every two inches. Put the bean seed in the hole, cover with dirt and tamp down lightly. If you’re growing pole green beans have the trellis in place before planting so that you do not disturb the roots.
Do Green Beans Need Full Sun?
Beans like full sun. Full sun is at least 6 hours a day. At the beginning of the growing season check which areas of your garden have full sun, partial shade, or full shade throughout the day. At a minimum check out your garden at noon and record how much sun different areas have. If you’re growing pole beans plan for them to have sun at their top height.
To augment the amount of light in your garden you can take a piece of cardboard and cover it with aluminum foil. Use the panel as a reflector and place it where it makes the most sense.
Although beans like full sun they do not do great in consistent high temperatures above 85 degrees. Putting mulch on the soil and regular watering can help keep the soil temperature down. Full sun also keeps the bean plant dry and disease free.
How Tall Do Green Beans Grow?
Green beans are separated into two main categories based on how the grow, bush beans and pole beans. Bush beans grow about 2 feet tall and 2 feet wide and like the name implies form into a bush. Pole beans can grow up to 20 feet tall and send runners sideways that are a foot long.
When you plant pole beans you want to have some sort of trellis in place so you don’t disturb the roots by putting it in and then start to train the beans up the poles as they grow. You may find a variety that is called a half-runner bean. These are in between bush an pole varieties and end up around 3-5 feet tall.
Watering Green Beans
Green beans need an inch of water a week while in the vegetative state and once they start flowering they need 2-3 inches of water a week. To check if the beans need to be watered stick a finger in the soil 3-4 inches deep; if it’s moist let it be and if it’s dry water. Another sign for when to water is wilting of the leaves. Wilting during a hot day is normal and the leaves should perk back up later at night or by the next morning. If you see wilted leaves early in the morning you probably need to water.
If you use a sprinkler to water do so in the afternoon so that the sun has time to dry off the leaves before night. Wet foliage can invite disease like powdery mildew. Use a rain gauge to determine how much rain has fallen and how much water your sprinkler puts off within a time range.
Fertilizing Green Beans
Beans are considered light feeders. You just want to make sure they have access to some amount of the basic nutrients. Fertilizers are labeled with a N-P-K ratio, that’s Nitrogen-Phosphorous-Potassium. These are the three main nutrients plants need followed by calcium, magnesium, sulfur, etc. This home test kit will tell you your soils nutrient levels for 13 nutrients as well as the soil PH.
Jack’s Classic is a standard all purpose 20-20-20 water soluble fertilizer. You can use half the amount the directions call for and make it a 10-10-10 fertilizer if you feel your soil is decent. Here’s a good organic fertilizer from Organic Plant Magic that measures 6-5-5 +Ca. It has beneficial bacterias and organic matters that have trace minerals.
Green beans and all legumes are nitrogen fixing plants. This means they take nitrogen out of the air and fix it into the soil. This is actually done by bacteria that the bean plants have a symbiotic relationship with. The bean plants play host to the bacteria that take up residence in the plants root systems forming nodules in the roots and the bacteria produce nitrogen the plant needs to grow. The bean plants are not very selective of their guests and will sometimes take up bacteria strains that produce little or no nitrogen. This soil inoculant will ensure that the bacteria taken up by the bean plants are beneficial nitrogen producing bacteria. This is just another way to organically improve your soil health.