Growing lima beans, sometimes called butter beans, inside your home is easy and rewarding. Because the growth cycle of lima beans is so quick and easy, this project is an ideal way to introduce children or gardening novices to the fun of growing edible plants. You’ll be able to clearly observe how a seed sprouts and transforms itself into a viable adult.
If you wish to begin from scratch, the easiest types if lima bean plant to grow in containers are the Henderson or Fordhook, as they grow into manageable bushes.
WARNING: If you plan to work with butter beans around children, know that you should never eat the raw beans. The raw fruit contains linamarin, a type of cyanide that can be potentially dangerous. The cooking process eliminates this toxin completely.
Step 1 - Germinate Seeds Using Paper Towels
Acquire several raw lima beans that are no more than one year old. Completely submerge them in warm water for a minimum of eight hours. Do not keep them submerged for longer than 24 hours.
If the seeds have failed to sprout by this time, sandwich them in between several layers of damp paper towels, and place the damp towels into a sealed sandwich baggie with air left inside. Keep the seeds in a warm environment, like a windowsill, until they successfully burst open and produce a small white sprout. Check the seeds each day, and spray the paper towels with more water when they seem dry. It will take four to seven days for the seeds to germinate.
The first sprout is actually the beginning of the lima bean's root system, so this is a perfect opportunity to teach a child about germination if you’re using this as a teaching project.
Step 2 – Sow Your Seeds in the Right Place and Right Depth
Acquire one to two 8-10 inch containers, fill the bottom 1/2 inch with gravel, and load the remaining space with organic potting soil. Make sure this potting soil is not high in nitrogen and is a time release blend. High nitrogen soil will encourage foliage growth but will actually hinder the growth of flowers and beans. Ensure the container has holes in the bottom for proper drainage.
Use your finger to make a hole in the soil 1-2 inch deep. Place a lima bean in the hole with its sprout pointed down toward the center of the pot. No more than 2 lima beans should be planted in one pot.
TIP: Gardening expert Rachel Klein suggests, "If you are interested in making your own organic potting mix, combine 1 part potting soil, 1 part perlite, and 1 1/2 parts chipped bark or compost. If you want to include a fertilizer, use an even 20-20-20 preparation or any vegetable fertilizer."
Step 3 – Condition Your Soil
After putting the sprouted lima bean in the pot, fill the remaining space with a light dusting of potting soil. Any sediment spread over the sprouts should be loose soil only. Butter bean seedlings are notoriously weak and cannot break through heavy soil layers.
Cover the top of each pot with a layer of plastic wrap to increase humidity and encourage growth. The pots should be placed in any sunny indoor location where it will receive more than six hours of direct sunlight each day. Pots should be kept in an area that will reach at least 70-80 degrees Fahrenheit. If your climate makes it difficult to achieve these temperatures indoors, place a heating pad underneath the pots and monitor it accordingly.
Step 4 - Care for Emerging Seedlings
Once the seedlings have sprouted above ground, remove the plastic wrap immediately to make room for the foliage. Keep the lima bean pots in an area with high sunlight for the entirety of their growth. Most varieties of lima bean need support to grow. Without support, the foliage will flop over the rim of the pot. As the bean plants grow, attach them to a support system using tomato wraps, dental floss, or twist ties.
Water them only after the top inch of soil has completely dried or if the foliage seems weak or brittle.
Step 5 – Pick Pods and Enjoy!
In the months following germination, your lima bean plants will begin to bloom and produce pods. Bean pods are ready to harvest when they are bright green, 3 inches long, and look plump and filled. Picking the pods as soon as they are ready encourages the plants to continue to produce fruit.
Lima beans are rich in protein, fiber, and magnesium. Hopefully, if you have young kids and want to indoctrinate them into the world of gardening, lima beans will be just the thing to spark their interest without intimidating them.
Plus, given that this plant can be cultivated indoors, if you stagger your plantings you can enjoy the delicious butter beans all year round!