There are several important stages in the cultivation of a plant and one of these is the planting of plants in pots. This is known as potting. The move is dictated by the vigor of the plant, especially in its root system. Once it outgrows its original soil area in a pot it is necessary to provide more room for the root development and the plant has to be moved on or potted into a larger pot. If the plant is being raised from seed or a cutting, it will be necessary to give it more root room eventually and the next move is into a small pot.
Although many plants will eventually be planted out into the ground, some will continue their growth and produce their foliage or flowering displays in pots. These must be large enough to provide adequate root room and feeding facilities. It will be appreciated, therefore, that the potting of plants is a progressive and logical sequence of events.
The time to pot plants must depend on what is being grown. Most of the general potting, however, takes place in the early part of each year—usually from February until late May.
Success with potting depends on the use of a suitable soil mixture. Fortunately one formula is all that is required as this contains all the essential ingredients in the correct proportions. This is the John Innes potting compost and it can be purchased, ready made up, from local garden shops.
Soilless composts are becoming increasingly popular with many gardeners. These are obtainable in various proprietary formulations.
Before potting begins it is important to make sure that all pots are thoroughly clean. Now that plastic pots have practically superseded clay ones, this is no problem. Drainage is important and clay pots will require small broken pieces of crock placed over the drainage holes, or special plastic mesh can be used for the plastic pots.
When the crocks are in place, a little coarse soil (the residue from the sieve is ideal) should be placed on top. This is followed by a small amount of the prepared John Innes potting compost or other mixture. To remove a pot plant for potting on into a pot of larger size, the pot and plant is turned upside down and the rim of the pot rapped smartly on the edge of the staging, bench or other suitable solid surface. If the fingers of one hand are kept over the soil and on either side of the plant’s stem, the loosened soil bulk can be guided out of the pot.
The plant should then be placed on top of the soil in the new pot and more soil should be carefully trickled or poured in around the inside of the pot. Gentle firming is needed and this is done with the fingers, pressing evenly all round but a little way away from the plant’s stem. A final sharp rap of the pot on the staging or bench will settle the soil even further, and any topping up with extra soil can be done afterwards. Make sure that the level of the soil is a little below the rim of the pot to allow for watering.
Where plants are being potted into pot sizes of 15cm (6in) and over, much firmer potting is required. This can be achieved with a short piece of blunt-ended stick. It is used as a rammer (not too hard) to compress the soil between the inside edge of the pot and the plant’s soil ball.
Make sure that the potting soil is just moist. Under no circumstances should the mixture be dry when potting is started. It is a good plan to soak the soil several hours before it is required, and then to allow surplus moisture to drain away. If the potting compost is neither too wet nor too dry, a handful when picked up and squeezed firmly in the hand should retain its shape, but should then crumble when thrown back on the heap of prepared soil.
Once the plants have been potted, they should be given shady conditions to prevent drooping or flagging. Blinds or a little shading spray on the glass will help. Keep the plants watered regularly but apply sufficient only to keep the soil moist. As soon as the plants have established themselves and overcome the slight check to growth which is inevitable with potting, they can be placed in full light.