When to sow beans outside: dwarf and pole beans

Why sow beans directly?

Beans are one of the easiest vegetables to sow directly into the ground. You buy no seedlings, you sow seeds where they grow, and within six to eight weeks you pick your first pods. This saves money and effort.

The reason is simple: bean seeds are large, strong, and forgiving. Unlike fine seeds like carrot or salad rocket, bean seeds germinate well in cool soil. They do not rot so readily if they sit in wet earth.

There are two main types: dwarf beans (bush beans) that grow compactly and pole beans (climbing beans) that climb. Both follow the same sowing timing.

Dwarf beans and pole beans: what is the difference?

Dwarf beans:

• Grow maximum 40-50 cm tall
• Need no support
• Ripen all at once (pod after pod)
• Good for small gardens
• Cultivars: Phaseolus vulgaris 'Mascotte', 'Tango', 'Cobra'

Pole beans:

• Grow up to 2-3 meters tall
• Need support (rows of stakes, string, framework)
• Produce continuously (pods grow underneath each other)
• Much higher yield per square meter
• Cultivars: 'Scarlet Emperor', 'Desiree', 'Neckarqueen'

Both taste from the same region, need the same feeding, and follow the same sowing timing.

When do you sow beans outside?

Beans do not like cold. Soil temperature must be at least 15-16 degrees to germinate well. Below 12 degrees they germinate barely, below 10 degrees they probably rot.

In the Netherlands and Belgium that temperature usually sits around:

• South Netherlands/Belgium: second week of May (around May 10-12)
• Central Netherlands: third week of May (around May 15-18)
• North Netherlands: fourth week of May (around May 20-25)

Practically speaking, you sow beans only AFTER the Ice Saints have passed (May 13) plus one more week. So for the whole breadth of Benelux: sowing after May 20 is very safe. In a warm spring, May 15 is fine.

Always check the 10-day weather forecast before sowing. If no more frost risk is in the forecast, then go ahead.

Ground preparation

Beans grow better in fertile soil, but are not fussy. They do like well-draining earth. Heavy clay soil needs breaking up with compost.

For one meter of row (roughly 30 beans):

• Add 2 liters garden compost per meter
• Work it in shallowly (15 cm deep)
• Make the soil smooth
• Water the row well a day before sowing

Beans fix their own nitrogen (they have nodules on roots with bacteria). You do not need to add nitrogen fertilizer. Phosphate helps a lot though (bone meal).

Sowing: directly into the ground

Sow beans 2-3 cm deep, with roughly 10-15 cm spacing between seeds.

Dwarf beans:

1. Make a row 2-3 cm deep with your finger or spade.
2. Place bean seeds in with about 12 cm spacing.
3. Cover with earth, press gently.
4. Water gently (not with a jet that washes seeds away).
5. Set labels so you know where they are (they are slow).
6. After 7-10 days the first shoots appear.

Pole beans: Set your support BEFORE you sow (stakes, string, framework). This prevents root damage later.

1. Set two rows of stakes 2 meters apart leaning toward each other.
2. Set string or rope between the stakes (wigwam shape).
3. Sow bean seeds at the foot of each stake, 2-3 cm deep.
4. Place no more than two seeds per stake (one grows bigger).
5. Water gently.
6. After 7-10 days the shoots shoot upward.

Germination time and growth

Bean seeds germinate fairly fast if warm enough:

• At 20 degrees: 7-10 days germination
• At 15-18 degrees: 10-14 days
• At 12-15 degrees: very slow, risk of rotting

The first two leaves that appear are seed leaves (plump, round). Then true bean leaves come (longer, jointed).

After one week pole beans already start growing upward. Dwarf beans grow more horizontally.

Feeding and water

Beans like consistently moist soil. Not wet, but not dry either. Water when the top 5 cm of soil feels dry.

Feeding: Every two weeks give tomato fertilizer or bone meal solution. Not more, or you get too much leaf instead of fruit (pods).

From flowering to harvest (roughly four weeks) phosphorus and potassium are important (fruit carrier). Nitrogen then held back.

Frequently asked questions

Can I sow beans earlier in pots indoors?

Yes, you can, but it does not pay. Bean seeds germinate and grow so fast your advantage completely disappears. Preference: sow directly outside. If you must: sow in pots around mid-April (in greenhouse or warm windowsill), then pot them out just after the Ice Saints.

How many seeds germinate?

With bean seeds usually 80-95 percent. So sow a bit extra, you always have a few duds.

Why do my pole beans not grow upward?

Three reasons: (1) Ground too cold (sown too early). (2) No support close enough (they prefer to grow horizontally). (3) Soil too dry (they give up in drought). Ensure warmth, support, and water.

Can dwarf and pole beans sit close together?

No. Dwarf beans like 12-15 cm spacing. Pole beans like 25-30 cm spacing (more food needed). Too close means fungal attack and poor yield.

Can I harvest them when they are small?

Yes, early harvesting is nicer (tender, no stringy fibers). Harvest dwarf beans when the pod is roughly 12-15 cm long. Pole beans let grow a bit larger (15-20 cm), then they bear more.

Step-by-step

Step 1: Choose sowing spot

Beans like sun (minimum 6 hours). Find a warm spot, preferably sheltered from strong wind.

Step 2: Ground preparation

Work in compost and bone meal. Make the row flat. Water a day before sowing.

Step 3: Set support (pole beans)

Set stakes or rope work before you sow. This prevents later root damage.

Step 4: Sow

Sow bean seeds 2-3 cm deep with 12-15 cm spacing. Cover, water gently.

Step 5: Protect from birds

Birds like to eat bean seeds. Lay mesh over the sowing row first week.

Discover your own garden design

At [gardenworld.app](https://gardenworld.app) you can upload your front yard and see where your bean bed fits best. Plant them where they get sun, and they produce for you all summer long.