Growing your own beans

Bill Brett | 11 December, 2021

            Green Beans NZ

What you need to know about growing beans at home.

Beans are a popular vegetable with gardeners along with tomatoes and lettuces. They are a healthy, tasty vegetable used in many dishes. There are a range of varieties and types which vary in size, appearance, colour, and dwarf or climbing. 

What soil conditions do beans require?

Generally they are easy to grow, but there can be challenges. Beans require a free draining soil to minimise the risk of several soil fungus diseases which attack them and also to ensure the easy uptake of nutrients and water. This is best achieved by adding lots of compost and raising the planting area above the surrounding soil.

Beans will do best in soil with a good base of lime, and a good balanced NPK fertiliser—one where the potassium level (K) is at least as high as the nitrogen (N).

More info on improving soil can be found here.

When should I sow bean seeds?

Beans require warm temperatures to grow and seeds will not germinate until soil temperatures are around 16°C. This is usually around mid-October if planting directly into the soil. I usually sow an early crop of dwarf beans in early September, raised in my germinating hot box with the aid of a warming pad. These are planted out in early October and we get our first pick on December 1st. 

Bean seed is very susceptible to physical damage from the jarring of harvesting, processing, packing and transport, which results in a lower germination of around 70 – 80%. Don’t use any broken or cracked seed, and sow a few extras to ensure the number of plants you want. For a continuous supply from dwarf beans I sow 10 seeds every three weeks from early September through to late December.

What variety should I grow?

My favourites varieties are ‘ican Supreme’, available from independent garden centres, or ‘Hickok’ available on mail order from Egmont seeds. With these varieties the crop is carried high, minimising disease, and making picking easy. The beans are short (12-14cm long), straight, tender and tasty. Cooked whole, they look great on the plate. Other good dwarf varieties are Yates ‘Chefs Choice’ or ‘Long John’.  

‘Scarlet Runner’ –remains a popular reliable variety for a climber which produces in flushes from Christmas through to March. Stringless varieties of Scarlet Runner are less prolific but better quality. Other climbing beans include the popular Fardenlosa type sold under several names including Mangere Pole, Blue Lake, and others.  

What pests will affect beans?

A problem with climbing beans apart from the fact they require a frame/trellis support, is that they are prone to insect attack because of their longer growing season. The rasp-sucking vegetable shield bug can totally destroy the crop by dehydrating the young beans. This is often followed by a build-up of white fly and looper caterpillars, and mites which brings harvest to a sudden end.Yates Mavrik + Grosafe Enspray 99 oil will deal with these pests, provided intervention is not left until too late.
For pest & disease control in vegetables we strongly recommend referring to ‘Garden Pest & Disease Control’ book for positive identification, prevention methods, and where required the best pesticide for purpose. Available from garden centres, or here on our website.     

When should I harvest the beans?

Harvest as soon as the pods have reached size as they become hard and dry if left to over mature.