February Gardener

science for the gardener 4Gardening, winter weather conditions and preparing for Spring 

Nature as we all know does what it wants to do and it might be worth our while looking at the potential consequences of the recent very wet and unseasonably very warm weather arriving in the UK  with strong southerly winds emerging from the the African continent.

Botanically we have all experienced unusual or unexpected flowering which may be a late second flowering from 2015 or too early Spring flowering, which is all very confusing for plants, gardeners and wildlife.  We have seen Daffodils (Narcissus) bulbs flowering in December, also Anemonies and Primulas (Ranunculus family) and many more plants jumping the gun and flowering a month early in December/January.  I have even had a summer flowering Ceanothus starting to bloom in January.  This is not a worry unless woody shrubs and herbaceous perennials flower in the severe frost that may well follow mild conditions with resulting damage to the flower heads and buds.  Even very hardy woody shrub buds such as those found on the Camellia can be badly damaged on a very cold sunny winter morning with sudden melting of the frosted buds.  We can try protecting them with garden fleece or bubble wrap if we are well prepared in time for frosts!

We may not like frosts, but many hardy plants do ,surprisingly, and nature comes to the rescue with plant Vernalisation, the name given to a sustained period of severe cold of between  +5 and -5 degrees for 5/6 weeks.This process initiates certain plants to flower at the appropriate time   Most vegetable biennials grow foliage in the first year and flower the following  e.g.Brassicaceae  (Mustard family ), brassicas ,cabbages, sprouts ,kale ,turnips ,carrots. Root brassica vegetables store food -carbohydrate reserves . Hardy herbaceous plants and many woody shrubs/trees should have this frozen period which used to be normal in Winter in the UK.   Also many standard flowering plants e.g. Campanula – Bell Flower (Campanula family), Chrysanthemums (Aster – Daisy family) and especially the fruit tree (Rose  family) require  this (vernalisation) sustained cold period or the consequences may be very delayed flowering and fruiting till late Summer or even Autumn!  This delay can be disastrous for loss of Spring ornamental flowering.  Vernalisation is  important in general for early vegetable harvesting, ornamental and fruit tree growing farms, e.g. Plums, Cherries, Pears, Apples etc all need that vital minimum few weeks  of a frosty start to the season. In some warmer countries artificial vernalisation has to be introduced which is an interesting subject to be covered at a later date.Light levels are also involved ,again another subject called Periodicity.

Ground – soil condition this month  Soggy soil will soon harden but with clay based loam water will lie trapped until better drainage/evaporation starts in the warmer weather in April/May some time after the long thaw takes place.  Add  organic matter e.g. compost, manure, leaf mould and inorganic matter e.g. grit, spare gravel, (even a small soakaway for large amounts of trapped water). On a positive note again we will need a good storage of water in the soil for those hot months we yearn for, remembering how quickly the ground dries up under grass lawns for example.

Pests  Our beloved gardeners’ friends, slugs and snails bless them, will now be so ecstatically happy and in March/April they will start reproducing big time from earlier perfect soggy conditions.  So be warned and try with tough gloves to remove them yourself at night or early morning (horrible job but better than slug pellets that can kill hedgehogs and harm other animals and pets!)   We will have fewer of our wonderful hedgehog friends, blackbirds, thrushes and other ground feeders sadly unless we all pull together and provide appropriate conditions for them.

(see Previous Gardening Year monthly NOV DEC JAN blogs 2014)

So while we don’t all appreciate bitter cold weather or excessive wet weather, horticulture needs it in moderation and aquatic-moisture loving plants adore it, so have a look around for some selections in your  garden centres.  You may save time searching by asking at enquiries for these more specialist plants and you may be able to search and even buy some on line !

I will be on a Botanical Tour in the Far East and Australasia in February and March so hope to follow up with some interesting reports of plants growing in tropical conditions.  I’m quite excited but don’t relish the long haul flights with no garden to walk round when I get restless.

Tony Arnold ACIHort

01/02/2016