How to Grow Healthy Beans

There is nothing nicer than home grown beans. A fresh bean with that snappy crunch when you are eating them raw is priceless. You can't get that crunch from shop bought beans, as they have been off the bush for too long. They are a warm season crop and are perfect for putting into summer salads. Beans(Phaseolus vulgaris are in the Fabacaeae family along with many other common plants. There are many different types of beans, runner, scarlet, board, french and more. Most beans are annuals. This means that they live between 6-12months. But Runner/Scarlet beans (Phaseolus coccineus are perennial beans and die back over autumn/winter to re-emerge in spring. They are also known as the Seven year bean because that is how long they live. Like all climbing plants, beans need support, even the dwarf varieties. However, the climbing varieties produce more beans than the dwarf (bush) ones. In warm climates, beans can be grown all year round, which gives you an excellent supply of fresh vegetables.

Cultivation Notes.

As with all vegetables, beans need a full sun position which gets 6-8 hours of sunlight each day. Beans along with other legumes such as wattles and green manure crops are able to fix nitrogen gas from the atmosphere. There is a symbiotic relationship between the roots and a bacteria called Rhizobium. The nitrogen is stored in the roots in swellings called nodules. The nitrogen is released into the soil when the plant dies and decomposes. Green manure crops such as russel lupins are often grown to about 50cm, then dug into the soil to refresh the nitrogen content of the soil. Beans are a great vegetable to plant after cool season broccoli and cauliflower which use up all the nitrogen present in the soil.

Beans like a pH of between 6-7 and if it is slightly on the alkaline side that is fine with them. Remember to lower your pH you add sulfur and to raise your pH you apply lime. In readiness for your planting beans whether seed or seedling, the soil needs to be open, friable and well drained. As with peas, bean seeds will rot if the soil is too moist. I recommend incorporating blood and bone, compost and cow or sheep manure. Another secret in the soil preparation is too add some potash. Once the beans have germinated you can apply a small amount of pelleted chicken manure. Liquid feeding regularly also helps to keep the plants healthy. But remember, too much nitrogen will prevent them from flowering and cause soft sappy growth which is prone to insect attack and fungal disease.

Hint: It is a good idea when they first start flowering to side dress the plants with a high potassium fertilizer.

For growing beans I think the ridge and furrow style is best as it makes picking and watering the beans much easier. To create a furrow, with your spade dig a trench on one side and pile the soil on top of the already existing soil. Then on the otherside do the same thing, piling the soil on top of the already existing soil. Using the back of a metal rake flatten the top of the ridge. This is where the beans are planted. The benefits of this method are that the soil drains really well, it is easy to walk along the furrows and they allow the moisture to slowly seep into the soil.

Seeds Versus Seedlings

I prefer to grow beans from seeds and sow directly into the veggie patch. I would only recommend sowing seeds in punnets to start them off is if your area prone to frosts. Beans hate frosts and it is important to know when frost finish in your area, so you can plan when to plant your seeds. I also find as beans seeds are big, that planting them in pots isn't satisfactory. Often small pots are used and the beans pop out. This especially applies broad beans which have a large seed. It is also the fuss that you need to bestow on the punnets, making sure the soil doesn't dry out or the cat decide it is a lovely place to sleep.

To ensure the seeds germinate, the soil temperature needs to be between 15C - 24C and the air temperature needs to be at least over 15C. Once the temperature goes over 30C for long periods, the plants will shut down and stop growing. Of course we can't control the weather, but this is handy information because it explains why some years the yields are poor.

Staking

Beans as with any climbing plant need some sort of structure to climb on. Some bean varieties can grow as tall as 2 meters. Pole beans which are excellent for small gardens and need a pole with some sort of chicken wire wrapped around them, so the beans can climb up. Dwarf beans only grow about 30cm high and will also benefit from having a least one wire to twine around. For ordinary beans there are several options. One is to put some tomato stakes at each end of the row and run twine or wire the entire length. Wrungs need to be about 30cm apart with the lowest one between only about 5cm -10cm from the soil. This allows the bean tendrils to attach to the wire and start climbing.

Or you can make your own obelisks out of bamboo or cane stakes. There are also metal ones available. From personal experience I have discovered if using obelisks to only put 1 plant per structure. There needs to be at least 50cm between each obelisk to prevent fungal diseases developing. The secret of growing beans is space which allows between plants. This allows good air circulation and sunlight to penetrate to the leaves. Space also helps stop the spreading of disease.

One thing I have learnt that the obelisk system doesn't work for broad beans. The best trellising method is the old stake in the ground with string or wire running the length of the bed. I found with the obelisk that the broad beans got powerdery mildew, it wasn't easy to pick the beans and the structure obscured the air flow. That year, I didn't get many beans.

For perennial beans such as scarlet runners trellis and chicken wire are excellent supports especially if they are up against the fence or the shed. Another interesting trick is to mix them in with other plants over an arbor, as the flowers are gorgeous and they are quite an attractive garden feature!

Flowering

Climbing beans takes between 10-12 weeks before the beans are ready to harvest and dwarf beans take between 8-10 weeks. It is a good idea to pick the beans daily as this will encourage the bush to produce more.

Beans are self-pollinating flowers so theoretically you only need one plant. However, you won't have many beans, it is better to have a row of them. Cross pollination by insects is possible but is rare because pollination occurs before the flower opens. Inside the petals, the anthers are pushed up against the stigma which promotes automatic pollination when the anthers open. Because beans rarely cross pollinate each other, no hybridization occurs between different varieties, so you can plant different varieties close together