We are continuing to see spring growth tracking along with many nice moments of gardening in the past week between the showers of rain.
Overall the winter has been mild but we must always be wary, cold snaps, wet weather and frosts are always possible. It pays to have frost cloth handy for any cold nights where frost may develop and cause damage to new and emerging buds.
Some of the most attractive of the early trees to be seen now around the city are the early flowering cherry varieties and magnolias. Fruit trees flowering now including some peach and plum varieties also make an attractive show. Camellias are reaching their flowering peak and many rhododendrons and azaleas are showing their first stunning flowers.
Many of our native kowhai trees are about to burst forth in bloom, the early varieties showing off their beautiful golden yellow flowers providing a feast for native birds such as wood pigeons and tui.
As soil conditions permit, gardeners can look forward to increased activity in the garden. It is a busy time for seed sowing, spraying, fertilising and preparing soil for vegetable planting in the coming few months. Planting of sprouted seed potatoes can be done now. Regular mounding up as the leaves come through the soil will ensure protection from any frost, as well as nice long stems for tubers to form on.
Many winter annuals such as primulas and polyanthus are right at their peak now and are making an impressive display. If you are into seed sowing, then now is the time to be sowing trays of summer vegetables and flowering annuals inside or in a greenhouse. These will be ready for planting out in late September or early October to give a well established summer show for Christmas.
Once the flowering of indoor cyclamen has finished, pot-grown plants can be transplanted outdoors into the garden in a sheltered location. They perform best under trees where they are well shaded where they will often perform for many years self-seeding and naturalising themselves.
Roses are starting their new season's growth. Regular sprays with Grosafe Freeflo Copper mixed with Enspray 99 Oil will help prevent fungal diseases and insect pests. Apply a mulch to all bushes along with a dressing of rose fertiliser. Prune hybrid tea and floribunda roses now if you have left them and feed all roses now as the new growth starts to come away.
Fuchsias and a number of shrubs grown for the colour of their stems in winter such as the red stemmed dogwood, smoke bush and maples can be trimmed for shape now so the new growth comes away compact and lush. This also will help to control the size of the plant if this is desired.
It is also time to prune hydrangeas. If this has not yet been done, trim down to a fat double bud to ensure you are not cutting off this summer's flowers. To keep the flowers blue and purple, feed now with aluminium sulphate (aka Tui Hydrangea Blue). For pink and red colours, fertilise with Tui Garden Lime.
It is time to divide up perennial and herbaceous plants, such as hosta and daylily, that have become congested. Replant the outside parts of the plants and throw out the centre portion.
Magnolias are one of the most striking of the early flowering trees and shrubs. We have many quite stunning specimens, coming into flower at the moment, dotted around the city.
The range is extensive containing many varieties of great horticultural merit, including the star flowered "stellata" types, a great array of "tulip" flower types and the magnificent evergreen types.
Choose your site for planting a magnolia very carefully, as they resent being moved or transplanted once they are established, especially deciduous types. Some grow into quite large trees and require ample space to make a great display. Avoid overcrowding them in your garden and do not cultivate ground under them as their fleshy roots are often near the surface and should not be disturbed. Plant them in a full sun position, sheltered from strong winds and where the roots can be kept cool. They enjoy moist rich free draining soils just slightly acid (pH 6.5) with plenty of organic matter added such as peat moss, well rotted animal manure, organic compost or leaf mould.
Always plant new trees from the garden centre at the same soil level as they were in their pot and stake securely. They do not enjoy the soil being excessively compacted so don't firm excessively around the tree as some like to do.
Mulching routinely insulates the shallow roots from direct sun and helps to retain moisture. Water frequently (without drowning) the roots as necessary while plants are getting established and during dry periods. A top-dressing with an acid fertiliser such as that suitable for camellia, rhododendron and azaleas or sheep pellets after planting and then in the spring once per year will maintain healthy growth. Note that these plants detest lime so never apply it.
Magnolias are rarely affected by pests and diseases with any problems usually due to unsuitable soil conditions or deficiencies. Pruning, if necessary, is best done after flowering only to reduce size and remove damaged branches.
Last week I talked about the New Release Magnolia Sentry; here are some other notable deciduous varieties;
Magnolia Genie: produces stunning blooms of deep rich purple and red. This tree can suit small and large garden situations alike only growing 3.5m high by 2m wide.
Magnolia Vulcan: produces deep port wine red flowers up to 25cm across. A Felix Jury hybrid that is much sought after and grows 4m x 3m.
Magnolia Cleopatra: is a recent introduction from Taranaki breeder Vance Hooper. Produces luscious purple blooms from a young age with a good show on the plants in the garden centre (some magnolias can take a number of years to bloom well). It will form a pyramidal shaped tree growing about 4m high by 3.5m wide in 10 years. A good feature tree.
Magnolia Stellata Jane Platt: this variety has been marketed as the very best of the pink flowering stellata varieties. It is stunning with gorgeous rich, deep pink flowers in spring, grows 1.5m in 10 years.
Magnolia Stellata Dawn: is a pink arguably as good as Jane Platt, its stunning pink blooms flower earlier during July and August prior to Jane Platt. Grows about 2.5m in 10 years.
Have a good week,
• Gareth Carter is general manager of Springvale Garden Centre