Action for November Pond and greenhouse
Around the pond
Continue to cut back dead material from marginal plants and divide any potentially invasive ones (compost the leftovers to prevent them spreading).
While they’re dormant, plants in containers can be lowered deeper into the pond to guard against freezing.
Cut off the leaves and flowers of gunnera, mulch the crown with straw and put the leaves over the top to protect the crown from frost.
In the greenhouse
- Check the temperature. Adjust the heater as necessary.
- Pot up amaryllis (hippeastrum). The top two-thirds of the bulb should sit above the level of the compost, and the pot should be no more than 2.5cm wider than the bulb itself.
- Stop watering cacti and succulents except Christmas cacti, until March.
- Thin out sowings of hardy annuals sown in trays and pots. You can also thin carrots that were sown in pots.
- Bring in potted agapanthus and lilies to a shed or unheated greenhouse to overwinter – they’re prone to rotting in the wet if left outside.
- Take root cuttings of perennials with thick, fleshy roots including phlox, oriental poppies and verbascums.
- Tidy up pots and seed trays to give pests fewer hiding places.
Grey mould can become a problem in greenhouses and conservatories when the temperatures are low and the air is damp.
To minimise infection, remove dead and dying leaves from plants, and water sparingly without wetting the leaves.
If you’re overwintering tender plants such as bougainvillea and citrus, check for mealybug (the colonies look like cotton wool) and scale insects (look for flattened scales) under the stems.
Prune out the infected shoots and scrub the insects off with soapy water.