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.
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?
A)# Sowing bean seeds in coffee cups filled with potting soil
Needed: empty plastic coffee cups, potting soil, empty flower pot, bean seeds.
B)# Filling with potting soil, sowing and watering
Put potting soil in each coffee cup. Press on the potting soil using a small plastic flower pot.
Lay bean seeds on the (compressed) potting soil.
Then put about 0.5 inch of potting soil on the seeds.
Press again on the potting soil using a small plastic flower pot.
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
Cover all cups with plastic foil. Put the foil loose over the cups. So air can pass to the germinating seeds.
Or put all beakers in a small greenhouse. Put on the transparent top.
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
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.
The beans on this photo have been sown in coffee cups or flower pots with potting soil. They grew against an attic window.
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.
Use the bulb planter to make a hole in the soil. Keep the soil in the bulb planter.
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.
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.
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.
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.
Take the insert out of the flower pot.
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.
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.
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.
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.
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.
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;
Eight days after sowing.
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;
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.
Flower pot with insert and garden soil/compost mixture, just before taking out.
Take the insert with rott ball and plants out of the flower pot.
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.
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.
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.