JUNE in the garden
Hands on dahlia division workshops are available on request either at your venue of choice or held by the C.D.D.C (central districts dahlia circle) Please email for details.
Overwintering beds can be done in lots of ways.
I like to set my beds up and then forget about them until planting time.
I have several different beds, all are either raised or on a slope.
When I have lifted the tubers May/June I put a thick layer of compost on the bed. I don't worry about digging it in. It is fully processed before applying. If you add every year then you will end up with a slightly raised bed and lovely friable soil to plant into and easy lifting next year.
After applying compost to the beds, I put a layer of old carpet on top. A thin strip either side of the stakes. It may need some weights on it to prevent the wind from shifting it. It can now be left all winter.
When it comes time to plant, you simply pull the two narrow layers apart about 10 cms and plant your tubers.
The carpet works as both weed control and mulch against excess water and drying winds and sun. It will last about 2-3 years and is free. Doesn't matter if it is wool or synthetic, both work well.
In this bed, I leave it uncovered over winter. The birds help spread the compost while they look for the worms.
This bed is under planted at the back with daffodils for a spring show. It's too difficult to spread daffodils out as they get in the way of tuber planting and digging.
Wind shelter comes from a hedge on the westerly side and camellias and rhododendrons. These shrubs enjoy the same slightly acidic soil so companion plant well. If you want to maintain aesthetics simply remove stakes until needed later.
This bed I cover with pea straw in the summer.
Tuber storage.
Everyone has their favourite way to store dahlia tubers, but you just need to follow a few basic rules.
Do not leave tubers exposed to rain, frosts or in a hot area. Label the tubers by writing on them directly either with indelible pencil or vivid pen. I also put written labels on the side of the sawdust so I can see what is in each box. I put mine in a bed of sawdust in a polystyrene box without the lid on. The box has holes in the bottom for drainage in the spring, when I start dampening down to promote shoot growth. It is large, but light weight and ideal for carrying your sprouted tubers out to the garden beds. There is no need to handle the tubers unnecessarily. I put all the crown ends to the outside perimeter of the box and have them slightly elevated so I can easily see when shoots appear. Try not to have them touching.
You can also wrap tubers in gladwrap! Divide them, make sure they are completely dry. Dust cut surfaces with sulphur or cinnamon if desired. Then wrap one tuber, roll it over and then include next tuber, roll it then add next one, etc. These can be stacked on a shelf, in a box, for the duration of the winter.
After lifting, tap stem to shake off excess dirt. Hose off gently if dirt is too sticky. Leave to dry. Take off any damaged or rotten tubers. You can dust cut edges with sulphur powder. ( available from any garden store). Lightly cover tubers with a dry to slightly damp medium to help prevent excess drying out and shrivelling over winter. I use sawdust as it is light weight and absorbs moisture well and holds it when dampening tubers in spring. I store my polystyrene bins in a garden shed, but you could put them under a hedge as long as they are covered to prevent rain and frost damage.
Any tubers that look suspect health wise should be discarded.
While tubers are dormant is the time to build your next compost heap for spreading on the dahlia beds next season. With lots of problems coming from contaminated potting mix/compost that is store bought, now is the time to learn how to build your own compost. As well as compost, I also grow a large vermicast supply. I make a strip about a 1m -1.5m wide and 5m long. Put old carpet down, heap as much horse poo as you can onto it, cover with old carpet. You can seed the pile with store bought worms. I think Bunnings still have them. I use horse poo because I have my own horse who makes kind donations. You will have to be innovative about sourcing your raw materials. A worm farm/ compost put down in winter is ready to use the following autumn.
You probably have your wishlist completed and are keen to start ordering. Remember that nz suppliers wont know what they have available until they lift, inspect and divide their tubers. Pre-orders can be made now but please do not buy tubers until sept/oct. You musn't buy until you can see viable eyes or shoots. If you buy prior to this you won't know if the tuber will grow. It is very hard to get your money back if you bought at the wrong time. Shame on those who sell tubers in the winter, often with very high prices.