Thursday 17th April, 2025
Hi
Short days and longs nights brings about big changes in leaves.
We often get questions at this time of year about leaves that don't look so good, may have some brown marks, torn and damaged or just generally look the worse for wear. The reality is that for deciduous plants, they have almost done their task for the year and that is one of producing food for the plant to grow, making sugar out of sunlight.
The colour change and the onset of leaf fall is primarily related to the fact that the day length is shorter and the nights are now much longer. As the nights get longer the leaves on our deciduous tree start a biochemical process.
There are three main pigments present and involved with leaves and the obvious one is chlorophyll which shows as green and is responsible for photosynthesis and the production of sugars to grow our trees and shrubs.
Carotenoids are also present in the leaves which provide the oranges, reds and yellows in nature and as we move into the Autumn and longer nights, more carotenoids and anthocyanins (responsible for blue, purple colours) are visible as the production of Chlorophyll starts to decline . As the chlorophyll becomes less, the colour of the other pigments, being the carotenoids and the anthocyanins are unmasked resulting in our Autumn colours.
Above: Nyssa sylvatica (Tupelo) looking gorgeous at the nursery today
Temperature and soil moisture also play a part in the Autumn process along with day length. I imagine the Waikato drought has brought about an early Autumn as trees survive dry conditions by some defoliation and often premature colouration occurs too. A sudden drop in, and cold temperatures will also help intensify the colours. Its often said that the Autumn colours in the South Island are spectacular due to their rapid decline in temperatures. On March 17th, Christchurch was sweltering in 30 degrees and today the high is 12. Brrr.
It is also at this time that the veins that carry the fluids into the leaves of deciduous plants gradually close off, forming a layer of cells at the end of the leaf stalk (petiole) thus becoming a separation layer and the point of abscission. The glue which sticks the leaf and branch together is called auxin and at this time of year its production falls creating a strain on the join. Often at this time of year and this point is reached, we can help nature and remove the leaves as they fall away quite readily from our plants.
Some classic trees and their colours
There are certain varieties of trees which are looking exceptional at this time of year. Red oak or
Quercus rubra rubra means red in latin, and so red is the Autumn colour of this handsome large tree.
Quercus palustrus known as the pin oak has pretty orangey red tones.
Ginkgo or Maidenhair trees are renown for their bright Autumn yellows.
Dogwoods or Cornus always seem to colour well, often in the fiery red shades, though some of the variegated ones are spectacular in purple, red and orange.
Nyssas or
Tupelo colour well in the Waikato and are also great in a wet feet kind of position. Ornamental pears Like Pyrus
Bradford and
Kea tend to lean towards bright red shades.
Liquidambars have long since been famous for their autumn shades ranging from yellows to orange to almost blackish purple depending on the cultivar.
A shout out to Persimmons which I just happen to have a soft spot for. Very pretty, lime green foliage in the spring and fiery red shades in the Autumn offset with attractive bright orange fruit that we are about to start picking. A defoliated tree can look stunning with its orange fruit decorating its naked branches ... if you can keep the birds off them... I know the Tui love them!!
Just arrived in and such great quality
I was in two minds about an email this week due to the the fact that it is Easter and it being two short week thrown in together. It was the quality of the stock that has just arrived that inspired me to share the new selections coupled with the fact that often a long weekend can be a time for projects like the garden. Add to that, it is great planting weather especially if the rain that is forecast arrives. I know that we are out and about planting tomorrow being Wednesday.
The Libertias have the common name of NZ iris and there are quite a few different species and their cultivars. Typically more perennial like by nature with sword like foliage and charming little iris like white flowers held at the end of stems. A plant that will tolerate most soil types and full sun through to semi shade. Generally these will clump or spread by sprouting from their roots under the soil.
Currently just in, we have
Libertia peregrinans which has the most attractive orangey foliage which makes for a great contrast in the garden again other foliage.
Libertia ixiodes has taller foliage than peregrinans but with yellow tinged green leaves and similar white flowers. Then there is
Grandiflora and as the name suggests this one has large flowers and the tallest of the foliage.
From our Aussie neighbours we have in again a couple of pretty cool Dianellas and these rate with me as great foliage plants that will perform in sun and lets say drier soil conditions.
Dianella Little Rev , Very attractive blue-grey, strappy foliage that forms a neat and tidy clump. Tough and hardy, requires very little maintenance once established. Dianella
Wyeena has narrow sword like leaves are shades of cream and green and quickly form a nice clump.
There is a collection of very beautiful and charming grasses or more specifically Carex oshimensis which are native to Japan and are a Japanese sedge. These have a wider leaf blade than many grasses and a very handsome cascading habit. I would imagine these would look pretty cool mass planted and will suit most soils and sun through to semi shade. I am not going to describe them all here but typically shades of green lime and cream and some variegated. Check them out Everest, Evergold, Everillo, Everlime, Eversheen and Featherfalls.
Nandinas are great value for the low maintenance garden and they are seriously easy to grow especially in full sun and drier soils. Nandina
Magical Lemon and Lime is a very popular choice with new foliage being attractive lime green that ages to green.
Obsession This selection of Nandina offers a compact and dense growth habit that grows slowly, producing bright red new growth that greens on maturity.
Gulf Stream This highly decorative form of the Chinese Welcome Bush is valued for the wonderful autumn foliage colour which intensifies to a brilliant red in winter.
Blush is a very nice selection of the more traditional Nandina with amazing winter coloured foliage.
Pittosporum Pot Belly is a newbie to me. A new cultivar of the crassifolium species but along the same lines of the Golf Ball series being compact and almost topiary ball shape in form but with the unique foliage of crassifolium. Got to be a goodie to give a go.
Sales and special of rose fruits trees and other stock line to make way for 2025 new intake
Roses.. they must all go ... looking fab value for just $30.00.
Selected fruit trees down to just $40 from $64.99 these are no longer showing in stock on the website so call on in to check out which varieties are there. These include Apples, Almonds, Apricots, selected Plums, Nectarines, Peaches, Pears some Figs and Quinces.
NZ
Natives small grade all normally $9.99 each select your ten for just $80.00
Cryptomeria japonica nice grade also for hedging $24.99 each or get yourself 10 or more for just $19.99 each
Opening Hours over the coming weeks - Easter and Anzac Day
We are closed Good Friday but open normal hours of 8.30am to 5.00pm Saturday, Sunday and Easter Monday. Anzac day being Friday the 25th April we are closed for the morning but open at 1pm until 5pm
The working week after Easter is very short being just three working days and so there is no South Island mail order deliver. Otherwise mail orders will go to local areas and to areas where we know that we can get delivery in time before the weekend.
Hopefully you will have time to enjoy the best of the autumn season this weekend whether its hot cross buns and chocolate, enjoying the brilliant autumn tree displays or achieving some progress on your garden project.
Its a long weekend for many ... have a fab Easter
Cheers from Lloyd, Tony and the Wairere team
