French beans are delicious-tasting and very easy to grow, no matter whether you have a large allotment or a tiny garden.
French beans are far easier to grow and provide support for than runner beans, and, although they are slightly less productive, the taste is generally better and the beans are stringless.
My favourite meal to make with French beans is a French bean salad. And my homegrown beans work best.
In this article, we will tell you the secret to growing dwarf French beans in your own vegetable garden.
First of all, let’s answer the question of why dwarf French beans and not climbing French beans.
Dwarf Or Climbing Beans – Pros & Cons
There are advantages and disadvantages to both dwarf and climbing French beans. However, the main difference between the two is that climbing beans grow very tall, whereas dwarf beans grow bushy and stay much smaller.
Because climbing French beans can grow over 2m (6ft), they need a lot of support. As a result, they also need quite a bit of space and aren’t really that suitable for growing in pots.
It’s important to keep tying new shoots to the support structure you have put up, which means they are more work than dwarf bean plants, which don’t need any support.
Dwarf French beans, on the other hand, don’t grow any taller than 48cm (19in), so will grow well in pots. This makes them ideal for smaller gardens, patios or balconies.
And because they don’t grow as tall, they start cropping earlier, normally in the UK in June, if you have sown the seeds in March/April indoors. But they won’t crop for very long, only a few weeks.
If you want to enjoy homegrown green beans for longer, you have to repeat sowing every few weeks. Or you grow climbing French beans, which will crop for about three months. Although they will start later, around July in the UK.
For these reasons, I prefer growing dwarf French beans. I do several sowings over spring and summer, which gives me a bumper crop of tasty French beans all summer long.
Best Dwarf French Beans Varieties To Try
There are quite a few good dwarf French bean varieties available. We would recommend that you try these:
Boston: this dwarf variety is a heavy cropper and produces beautiful, dark green beans that are very tasty. They are also ideal for freezing.
Purple Teepee: this French bean plant produces purple pods that will turn green when you cook them. The beans are stringless and taste delicious. This is an Italian variety, but grows well in the UK and will give you a good yield.
Adoration: producing yellow beans, this French dwarf bean variety is not only tasty but will also look beautiful in your garden. This French bean plant originates in France and is said to have an exquisite taste. It’s also a heavy cropper. I love growing dwarf French beans that aren’t green, as they look so beautifully exotic.
Sowing & Planting French Beans
French beans are delicate, so frost and cold weather are bad news for them. So they are best started indoors, in a cold greenhouse or windowsill.
Seeds should be sown mid-April in pots, roottrainers or toilet roll inners. Plant the seeds with the “belly button” side up, it’s easy to see which side this is when looking at the seed.
If you want to protect your dwarf French bean seedlings from transplant shock, you could use soil blocks to start them off. If you want to know more about gardening with soil blocks, you can read our article about this topic.
It’s worth noting that seeds can be sown directly outdoors, but have a lower success rate.
Germination time for French beans is usually 7-14 days depending on the weather conditions.
Once germinated, it’s essential to keep the plants out of drafts and cold weather, even a little frost will kill French bean plants. In late April, a cold greenhouse or cloche is usually enough to keep the plants safe from frost.
The plants can stay indoors for around 4 weeks, at which point they will begin getting too large for their containers.
It’s important that the risk of frost has passed before transplanting, or that you provide some sort of protection (cloche or fleece).
Planting out should be into a fertile bed that has had well-rotted manure or compost added to the soil the previous autumn.
And make sure you give your French bean plants a sunny spot, as this is where they will thrive best. They will tolerate light shade, though, if you can’t give them a sunny position.
A general-purpose fertiliser can be added to the soil 2 weeks before planting. Although French beans are a hungry crop, they are not as heavy feeders as runner beans, so they require far less soil preparation.
Make your own liquid fertiliser to feed your hungry bean plants.
Growing On & Caring For Your Beans
Once in the ground, the dwarf bean plants should begin to grow very quickly, with harvests of dwarf varieties being ready as early as late June.
While they don’t need much support, you can put a stick in for them to keep the pods off the ground. But generally, this is not necessary.
Water your dwarf French bean plants regularly, as they need a lot of water to give you the best yield. Especially once they flower and produce pods.
If you are growing dwarf French beans in a pot or container, regular watering is even more important because the soil will dry out quicker.
Make sure your soil is not waterlogged, because French bean plants don’t like that. Good drainage is vital.
Top Tip: To keep the soil moist, cover it with mulch, such as well-rotted manure or mushroom compost.
A liquid feed (such as seaweed) can be applied, but in most cases isn’t required. If the plants begin to look weak or depleted (especially after harvesting begins), a liquid feed will restart the growth and keep the plants producing.
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Beans, like other plants from the legume family, are excellent at producing their own rich soil. They do this by getting nitrogen from the air and then releasing any excess nitrogen into the soil.
That’s why they are great companions for other plants and are a star of companion planting.
Make sure you keep weeds at bay, as they not only steal nutrients from your bean plants, but can also attract diseases.
Harvesting Your Beans
Harvesting dwarf varieties is very easy as they are easily accessible. Look carefully for the beans as they always seem to be hiding. Allowing beans to reach maturity means the plant will stop producing new flowers and beans.
So regular picking when the pods are around 10cm (4in) will ensure that your dwarf runner bean plants will continue to produce more beans.
Unlike runner beans, you don’t have to worry quite so much about French beans becoming stringy, as long as you pick them when they are still young and don’t let them grow to maturity.
Once the beans start producing, you can expect them to continue growing strongly for a few weeks. If you want to be growing dwarf French beans throughout the summer, sow new plants every few weeks.
Pests And Diseases Affecting French Dwarf Beans
No guide about growing dwarf French beans would be complete without mentioning the pests and diseases that could affect your French bean plants.
Pests
Because French beans are delicious, not only humans like them, but also some pests do.
Slugs are one of them. They love the fresh and juicy leaves of the seedlings. So you need to protect your young French bean plants to prevent slugs from ruining your chances of tasty homegrown French beans.
There are many ways to prevent slugs from getting at your plants, but most of them aim to kill them. Slugs and snails are very important to our ecosystem and do a vital job.
So we recommend protecting your seedlings by covering them with a plastic bottle. Squash bottles work well. Just cut them in half and place the top half over your seedling. To make absolutely sure, put some insect mesh over the bottle opening.
Once your seedlings have grown into strong plants, slugs are less likely to eat them. Plus, they will be strong enough to tolerate the odd nibble from a slug.
Aphids are a very common pest, and the black bean aphid loves French beans.
These little insects suck the sap from the plants and cause stunted growth. A heavy infestation can even kill a plant.
They are tiny, round, black insects that will be easily visible on your plants.
To make sure black bean aphids don’t ruin your French bean plants, here are some things you can do:
- If you are not squeamish, pick off any aphids you see with your fingers and squash them
- If there are too many, put some newspaper on the soil around the plant and gently shake it. Only do this if your dwarf French bean plant is strong enough. The aphids will drop onto the paper, and you can then move them to a different part of the garden, where they won’t do too much harm.
- You can also wash your plants with insecticidal soap, which will get rid of the aphids.
- Pure organic cold pressed neem oil concentrate unrefined one 1000ml bottle
- Gentle biodegradable liquid soap derived from plant oils one 1000ml bottle
- Combine together with water to form a neem spray or drench
- You can also keep the aphids away by using companion planting. You can grow marigolds with your French beans, as they will repel aphids.
If you want to know more about companion planting, you can read our guide on companion planting for vegetables.
Diseases
One disease that you should have an eye out for when growing dwarf French beans is runner bean and French bean rust.
This is a fungal disease that affects the leaves of French bean plants. An infected plant will have pale, raised patches on top of the leaves, with white ones on the bottom.
The white spots will turn brown or black further into summer and move to the top of the leaves, too.
Depending on the severity of the infection, the plants might have stunted growth and a lower yield, or could even wilt and die.
Once your dwarf French bean plants are infected, there is nothing you can do. If the infection is mild, you can still eat the beans. If it is heavy, you will have to dig up the plant and dispose of it. Do not compost it.
So the best way forward is to try and prevent an infection. Here are some things you can do:
- The disease likes wet weather conditions, so make sure you plant your French bean plants far enough apart to allow for good air circulation. This will ensure that the foliage dries out quicker after rain, lowering the risk of infection.
- Water plants from below, rather than from above. This will keep the leaves drier.
- Keep your beds free of weeds and plant debris.
- If you spot any symptoms of the disease, remove the infected leaf immediately and destroy it.
- Practice crop rotation as this will reduce the risk of diseases building up. Include plants that are affected by the same disease, such as the legume family.
Bean powdery mildew is another fungal disease that could affect dwarf French beans.
Powdery mildew is easy to spot. You will see a white powdery layer on the leaves. This will block the pores of the plant, which will prevent it from photosynthesising and therefore feeding.
This will lead the plant to stop growing and finally die.
Again, prevention is the best option. Here are some things you can do:
- The disease tends to infect weak plants, so make sure you keep your French bean plants healthy by watering them regularly. But don’t overwater them.
- Water from below, to keep the foliage dry.
- Space out your plans to make sure air can circulate and dry out the foliage after rain.
- Practice crop rotation, as the spores can overwinter in the soil.
- Weed regularly and remove any plant debris.
- When your dwarf French beans get towards the end of their cropping cycle, remove the plants. As they will start to weaken, which makes them more susceptible to the disease.
Now that we have shown how easy growing dwarf French beans is, you can look forward to a summer full of delicious homegrown French beans.
