April, May and June are the months for houseplant repotting. 

Winter seems like the perfect time for indoor gardening but your houseplants will be happier if you leave them alone until spring. 

With long days in April, average temperatures are higher, your plants will be growing actively and roots quickly fill the new compost. Theses are the perfect conditions for repotting but only if necessary. 

Re-potting in April is best because your plants are ready to grow new roots in the warmer temperatures. Also the longer days enable your plants to evaporate (transpire) extra water. 

These conditions start to reverse after mid summer’s longest day and by the end of July your house plants won’t have time to root into the new compost. More later on. 

When you repot any plant you may be doubling the volume of compost in the your new pot even though the pot might only be the next size up. 

To enable your plants to grow quickly after repotting water the plant before hand. ‘Pot on’ into the new pot of compost but keep the new compost as dry as it comes out of a fresh bag. This means the roots have to search for water in the new compost. 

Repotting when the days are short, average temperatures lower at times of little growth can damage the your houseplants root due to the extra compost retaining too much cold water.

This becomes critical in winter. This extra compost can hold a lot of cold water and this can damage the roots if you re-potted indoor plants in autumn and winter.

Usually when a plant is over-watered it kills the roots. When roots are killed or badly damaged the plant wilts due to lack of water in the plant. This may ‘make’ you increase the watering to overcome the wilting, but unfortunately this makes the problem worse. The plant is in fact short of water because the damaged roots can’t take up water as normal. 

We recommend avoiding repotting after the end of July. This allows your houseplants roots to grow and fill the new compost before growth slows in September. This helps avoid over watering and root damage. 

NOTE: as the days shorten in mid to alte September house plants need less water at the same time as the transpiration decreases in the plant too, doubling the impact of over-watering. 

Tip: Acclimatise your compost up before repotting. 

If your compost is stored in your cold shed or greenhouse or it’s a new bag from Ferndale bring sufficient compost into your home 24 hours before you plan to pot to warm it ready for re-potting. This stops the cold water damaging the roots too.