32) Sowing beans in pots and planting in the garden later

Jantina, a Dutch lady, has put a comment at “Sjeftuintips” tip 12.  She writes that she sows bean seeds in coffee cups with potting soil. When bean plants are about 2 inch high, she pushes on the bottom of the cup and takes out the bean plants together with the root ball. Plants with rootball are put in the garden soil.

boonbeker 22

I wrote to Jantina that I would try this method too. I have done that and here are the results.


Sowing when and where to plant out?

Further in this tip you can find useful procedures to grow bean plants in pots.

When you want to grow beans early in the season, sow or germinate low beanplants (bush beans). Within some weeks bean plants are big. A few days later first flowers are there. And a short time later the first little beans are there. Pole beans take many weeks to grow to the top of the stake. Not until then, first flowers appear.

Sow or germinate bean seeds indoors at the beginning of April. Temperature about 20 to 25 C (68 to 77 F). After 7 to 10 days, bean plants are visible above the sowing soil. Or after about 1 week germinated bean seeds are that big that you can put the plants in a flower pot with garden soil or potting soil or compost. Take care to have (3 or) 4 bean plants per pot; sow 4 seeds in a flower pot or plant 4 bean plants in a flower pot.

Put the pots with little plants on a very light place, for example before a cold bed room window. Temperature must be about 15 C (59 F) so plants get used to lower temperatures. Keep them there for about 5 days.

boonpot 13

Next step is having the plants outside by day (when temperature is between 5 and 15 C (41 to 59 F). During the night keep them indoors at about 15 C (59 F). Keep the plants indoors by day when temperature outside is below 5 C (41 F). You can put the pots with bean plants in a laundry basket. Put the basket out by day and indoors during the night. The wire netting is there to keep the blackbirds out; bean plants grow well in homemade compost containing some earth wurms.

From mid April on, you can put the flower pots with bean plants (close to each other) in the garden soil. Put them under a tunnel or in a greenhouse. You can use a tunnel made of transparent corrugated plate (see tip 13). At warm weather, open the tunnel “a little” by day and close it during the night. At very cold weather lay plastic foil on the unnel.

From end of April on, you can take the rootballs with bean plants out of the pots and plant them in the garden soil. Distance between groups of plants is about 30 cm (12 inch). Put each rootball with plants in a mixture of compost and garden soil (ratio 1 to 1). Put the plants under a tunnel of corrugated plate (1 row) or under a tunnel of plastic foil (3 rows). Description of these tunnels see tip 11 or tip 13. From mid May on, the tunnel above the plants can be opened during day and closed at cold nights. And some weeks later tunnel can be taken away.


A)# Sowing bean seeds in coffee cups filled with potting soil

boonbeker 1

Needed: empty plastic coffee cups, potting soil, empty flower pot, bean seeds.


B)# Filling with potting soil, sowing and watering

boonbeker 2

Put potting soil in each coffee cup. Press on the potting soil using a small plastic flower pot.

boonbeker 4

Lay bean seeds on the (compressed) potting soil.

boonbeker 5

Then put about 0.5 inch of potting soil on the seeds.

boonbeker 2

Press again on the potting soil using a small plastic flower pot.

boonbeker 6

Spray water on the compressed potting soil with seeds.

Tests show that compressing potting soil and spraying water on the soil give the best germinating results.


C)# Covering the cups

boonbeker 8

Cover all cups with plastic foil. Put the foil loose over the cups. So air can pass to the germinating seeds.

boonbeker 10

Or put all beakers in a small greenhouse. Put on the transparent top.

boonbeker 11

Both vent holes in the top are a little bit opened. There is air flow and the potting soil does not dry too fast.

Put the whole at 19 to 22 C (66 to 72 F).


D)# Plants visible

boonbeker 12

boonbeker 13

The greenhouse with coffee cups after 7 days of germination at 19 C (66 F). In all cups there are some beans germinating. There is no water added during the 7 days.


E)# Cool and before a window

When first “stems” of bean plants are visible, as shown on the last photo above, put the cups in a cool room and before a window.  Temperature is about 15 C, 59 F. The bean plants grow to robust plants. Regularly spray a little water on the potting soil. Adding too much water can cause rotting beans. Let the plants grow in the cups until about 4 inch above the soil.

At my first experiments I took the plants too early out of the cups (see further). So I sowed new bean seeds in coffee cups.

boonbeker 18

The beans on this photo have been sown in coffee cups or flower pots with potting soil. They grew against an attic window.

boonbeker 20

boonbeker 19

When the plants are bigger and temp is okay, you can put the cups and pots in the garden soil. At cold nights, put a transparent tunnel over them.


F)# Planting from the coffee cup into the soil

When plants are about 4 inch high, you can take them out of the cups and put them into the garden soil. This goes well when using a bulb planter.


boonbeker 22

Use the bulb planter to make a hole in the soil.  Keep the soil in the bulb planter.

boonbeker 23

Jantina’s method;  lay the cup with plants aside  on your hand. Carefully press against the bottom of the cup. Move the cup and pull the cup carefully from the root ball. The plants have a rather big root ball, as visible on the photo.

boonbeker 24

When the bean plants are big, there are many roots growing in the potting soil. You can clamp the plants without the root ball falling apart.

boonbeker 25

Put the plants in the hole in the garden soil. Then shift some earth against the plants and into the gap between root ball and hole. When needed drop some earth out of the bulb planter and shift it against the plants.  Then open the bulb planter on an “empty” place in the garden to remove the earth from the bulb planter.


G)# Planting from the flower pot/insert/strip,  into the soil

In stead of a coffee cup, you can also use a plastic flower pot with insert and strip. This type of flower pot has been described at tip 30. Fill this flower pot with potting soil and sow beans in it.

boonpot 1

On this photo the flower pot has been filled with potting soil and there are big bean plants in. Top diameter of the flower pot is about 3.5 to 4 inch.

boonpot 2

Take the insert out of the flower pot.

boonpot 3

Pull the strip a few millimetres (about 1/4 inch) to above. Then release the strip. This will loosen the root ball. Take the root ball with plants from the insert with strip.

boonpot 4

When the bean plants are big, there are many roots growing in the potting soil. You can clamp the plants without the root ball falling apart. Then you can put the plants in the hole in the garden soil.


H)# Planting from a lowered coffee cup into the soil

You can cut the top part of a coffee cup. The cup gets lower then and it will contain less potting soil. The roots of the bean plants will not grow so deep to form a root ball. Maybe you can take the plants with root ball earlier out of this lowered cup than out of a normal cup. I did not test this effect; all plants in all cups have grown for the same number of days.

boonpot 10

Take the plants out of the lowered cup using the same method as at the normal cup. There are many roots in the root ball.

boonpot 11

Also at a lowered cup you can clamp the plants without the root ball falling apart. Then you can put the plants in the hole in the garden soil.


I)# Planting from a normal coffee cup,  containing less potting soil

You can fill a normal coffe cup with potting soil for half of the height. The plants do not grow so deep to form a root ball. Maybe you can take the plants with root ball earlier out of this half filled cup than out of a normal filled cup.

boonpot 9

At my test the plants did not grow so big in the half filled cup. The root ball is moist and there are few roots in. Maybe the plants got too much water or less water evaporated in this cup due to the high edge.

boonpot 12

The root ball with plants has been put in the cup again. Let the plants grow bigger.


J)# Too warm or too dark

When the plants grow in a room with a high temperatuure and/or not close to a window, plants will form a thin long stem with small leaves. See photo below;

boonbeker 14

Eight days after sowing.

boonbeker 15

Nine days after sowing.

At these plants stems are 2 inch high. But the roots do not grow deep into the potting soil.

When you take the plants and root ball out of the cup, this will happen;

boonbeker 16

boonbeker 17

The plants have a small root ball. At the bottom of the cup there is loose potting soil. Root ball falls apart.


K)# Sowing beans in a flower pot/insert/strip,    with garden soil/compost mixture

You can use a mixture of garden soil and compost (1 : 1) to sow beans in. The root ball will fall apart easier, because garden soil and compost contains less fibers than potting soil.

Then it is better to use a flower pot with insert. When planting in the garden soil you can easily take the root ball out of the flower pot. But at the root ball there is a high risk of falling apart, so handle carefully.

boonpot 5

Flower pot with insert and garden soil/compost mixture, just before taking out.

boonpot 6

Take the insert with rott ball and plants out of the flower pot.

boonpot 7

Lay the insert with root ball and plants on your hand. Carefully roll and turn the insert on your hand until you can take away the insert. Take away the insert and keep the root ball lying on your hand. At the root ball there is a high risk of falling apart, so handle carefully.

boonpot 8

Keep your hand with root ball and plants near the hole in the garden soil. Carefully let the whole slide into the hole in the garden soil.


L)# Summarized

Sowing beans in plastic coffee cups works well. Some things need special attention.

  • When sowing in coffee cups the amount of water added is critical. Too much water can have the seeds or plants rot. Or plants grow slowly.  When adding too little water, seeds or plants can dry out or plants can grow very slowly.
  • Let the plants grow in the cups until root ball contains many roots. Otherwise root ball can fall apart when planting in the soil.
  • Plants must grow in a cool light room to get robust plants and big root balls.
  • When using plastic flower pots with holes in the bottom, watering is less critical. So little chance of rotting seeds or plants.
  • Potting soil contains many fibers. You can clamp the plants without the root ball falling apart. Easy at planting into the garden soil.
  • When you sow in a garden soil/compost mixture, rott ball will easily fall apart. Use a flower pot with insert and let the root ball carefully slide into the hole in the soil.
This entry was posted in Beans, sowing. Bookmark the permalink.

2 Responses to 32) Sowing beans in pots and planting in the garden later

  1. I use coffee cups a lot for growing from seed. But for beans I use the cardboard tube in a toilet roll and just put the whole thing in a hole formed with a bulb planter and refill around. The cardboard rots away and the roots naturally go deep to the bottom of the roll.

    • Hello Alan,
      Thank you for your tip about sowing beans in cardboard tubes.
      I knew the cardboard tube sowing method already, but not for beans.
      And I want to complenet you with your fantastic blog.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s