Bring your Dahlias back to life
Set your dahlia tubers up in boxes, if you have not already done so, now is the time to get those tubers back to life. I started some of the tubers back to life in January to try and get some early cuttings from my dark leaf seedlings of the Pathfinder Collection. This is the way to multiply your stock. First you will need to find a fairly deep seed tray or those blue mushroom boxes; you can usually pick them up from your local supermarket. Start by making sure that the boxes you are using have holes in the bottom to let the excess water out. Put the compost in the boxes about half full (You can use multipurpose compost for this), place your tubers on top of the compost then lightly sprinkle more compost around the tuber, just below the crown. Don't forget to place the name label next to the tuber so you can remember the varieties name. Once you have put all your tubers in the boxes or trays you can give them a drink of water, maybe this is the time you have a cup of tea. Then you will need to put them in a warm place around about 20% centigrade in a fairly light place, then you can leave them for a week or so, they will start to make root, as they make root they will becoming back to life you will see that they will making small shoots. You can start to give them a fine spray this will help the small shoot to grow. but don't get the compost to wet Some varieties send a thick shoot up first let this shoot get to about a inch and a half long then cut it of with a sharp knife just below the first two leaves you can through that cutting away as it will not root for you. You will see from where you cut the last cutting of there will start to grow four more cuttings.
The ground where my dahlias are grown is
quite heavy, so digging can be delayed until March, If your ground contains a
proportion of clay, then it should be rough dug from November onwards to allow
the winter frosts to work on the soil, improving the nature of the clay
soil. Clay soil needs a large amount of humus (farmyard muck) to be incorporated
or I give my plot 6x, again improving the soil structure and helping to provide
food for the following year's plants.
but for the slugs I use something called Slugit you just spray it all over the compost and the tuber, this will last a week or two before you have to do it again. This winter has been a bad winter for keeping tubers I have had a lot of dahlia growers getting in touch with me to see if I can supply certain varieties some grower say that the plants never made a tuber, I like to grow pot tubers, this way you can keep your stock, as they only make a small tuber and they are easier to store over winter and as you set them up again they don't take up as much room on the bench. So as your tubers start to come back to life three thing to keep your eye on are, don't give them to much water as this will rot the tubers, you can almost let the compost dry out, second keep a look out for the greenfly and third check for slugs. Slugs will soon make a mess of the tiny shoots.
We talk about taking cuttings So that I can take cuttings early, I grow my tubers under fluorescent lights. This gives the tuber more light to grow and produce more cuttings. I leave the lights on from 4pm to midnight each day and as the evenings get lighter I move the afternoon time later and so on. The Dutch farmers grow there tubers in the dark at a temperature of about 60 degrees faringheight the only time they get any light is for watering the tubers and checking for disease and as they take the cuttings so the cuttings are yellow when they are taken, but as they are moved into the Polly tunnels as the days go by with in a week they start to green up. Some dahlia growers take part of the tuber with the cutting so they root easier. I use a Stanley Knife blade to take my cuttings I have a number of blades that I use, each time I take cuttings from a tuber I use only one blade after I have taken all the cuttings from the same tuber I clean the blade with a sterilizing solution ether methylated spirits or the tablets that you get from the chemist for sterilizing babies bottles any of these are ideal for this, I keep a small bottle ready made up next to the propagating bench. The cuttings I take are about four inches long I cut them just below a leaf joint, and then I remove the bottom two leaves. The compost mixture I put them in is about half compost and half sharp grit sand, I get about half a bucket of each and mix this together until I have made up enough to fill a 75lt compost bag that will keep me going a day or two. Then I either put the cuttings in individual cells depending on how many cuttings of the same variety I take or I put 8 or 10 of the same variety in to one 3 inch pot this way they all seem to grow the same height. I take cuttings right up to the end of May as I can use these cuttings to grow on as pot tubers for next year. After you have taken the cuttings and put them in the compost place them in the propagator about 20% centigrade give them a good watering and don't water again until the compost is almost dry, If they start to wilt you can give them a spray over the top to freshen them up If the days start to get sunny and very warm in the greenhouse but it is still to cold to open the windows or door, you can place some newspaper over the cuttings to shade them from the bright sunlight and give the newspaper a spray this will help to keep the cuttings fresh. If all the conditions are correct then the cuttings should start to root in about 14 days, the first cuttings you take from the tuber always seem to take the longest to root. Donít forget to keep your eye open for those pests; they will soon make a mess of your cuttings.
Getting your plot ready
Now that the nights are starting to draw out, and after a day in the office or factory it is nice to get out on to the plot and start to get the ground sorted out. First if itís full of weeds like dandelions and dockings you have to dig them out and put in the dustbin, it's no good putting them on the compost heap as they will only start to grow again. Once they are all removed then you can put the rest of the weeds on the compost heap. One of the best fertilizers you can put on your plot is farmyard manure, or as the late president of the National Dahlia Society (Derrick Hewlett) did, go to your nearest zoo and get some elephant manure I think they would be pleased to get rid of some. I put 6x on my plot or a similar type, Rooster or any concentrated mix that you can get from your garden centre. You can ether spread the manure all over your plot and dig it in, or trench each row and put the manure in the bottom of the trench. I rotavate my plot 2 times, I rotavate the first time, the opposite way that I am going to plant my dahlias as my ground is heavy, this way it helps to break my soil up, the second time as I rotivate I spread super phosphate on the ground. 25kg bag spread over 12 meters by 45 meters that's the size of my plot. Super phosphate is used for making root at the start of the plants growth, so they get established fairly quickly. As we are doing all this the tubers are making more cuttings for us to take and the early cuttings we took may need potting up in to a bigger pot so that they don't get pot bound. We must also keep spraying with a systemic insecticide for all the predators that like the lush fresh plants. Some of the plants will need to be moved from the greenhouse in to the cold frame to start to harden them of, but don't forget the cool nights if there are signs of frost you will have to cover the cold frame over at night with an old blanket or carpet, and don't forget to take it off again in the morning. If, the day start to warm up, open the frame a little to stop them from getting to hot.
Growing Dahlias in Tubs and Troughs
Thereís more to dahlias than tall flowering types that you see around the shows. There are also types that are ideal for growing in tubs and troughs. I have even grown some in hanging baskets, as a centre plant. They are good in small borders also; even some of the park departments are growing them, to put them in large beds. Some of the varietyís that are good for all this are, Exotic Dwarf a pink single with a darker pink in the centre, it grows eight inches tall this is a lovely little flower (flower size about one and a half inches across). Grow this with one named Omo, this grows the same size flower. A really bright white flower, I think this was named after the washing powder Omo. Then there are the Topmix varietyís in all different colours and the Lillyput types Red, Yellow, Pink, Orange Bronze and Purple. These varietyís you can get from the Garden Centres and Superstores that sell gardening sundries. They were raised in Holland and are grown there like we grow potatoes, and are harvested in the same way; they put them into what I call Dutch Bags with the photo of the flower on the top of the bag. Thatís how we get them in the Garden Centres. But one of my favourites is one called Little Dorick raised in England it has a little flower Lilac with a Purple ring around the centre. I was in Holland last year and we ordered some plug plants from a nursery man Cornelius G de Ree. These were New to the UK, a new type of dahlia raised by a Mr Renť Rotaveltts from just outside of Amsterdam. They are small patio dahlias of eight varietyís Amazon Bronze, Amazon Lilac, Floral Star, this has tiny Orange flowers about one inch across, Dahlstar Rose with Eye pink semi double, Dahlstar White, Dahlstar Red, Dahlstar Yellow, and a dark leaf one named Jewel Lilac this has a dark Lilac flower with a Black centre one I think will do well in the years to come. They all grow about eight inches tall. If you are going to grow any of the ones I have mentioned, you will need about three tubers to a container of about fifteen inches across. Put some small stones or old broken earthen ware pots in the bottom of the container to help for drainage (donít forget to make some holes in the bottom of the container to let the water drain out if it gets over watered).
Dahlias like water but donít like to
just stand in it. Then half fill your container with multipurpose compost mixed
with some sharp sand, the sharp sand helps to give the compost some body and
also drainage. Then place your tubers in the compost, at this stage I mix with
the rest of the compost and sand some water gel granules and some slow release
fertiliser. This will produce a very nutritious growing media that will help to
keep the plants fed through the summer and help to hold moisture. Put this over
the top of the tubers, about one and a half inches below the rim of the
container, give it a good watering and place in the greenhouse or conservatory
until all signs of frost has gone. Then wait for the small shoots to appear.
Hope you have some fun trying this out, I donít think you will be disappointed.
Potting Your Dahlia Cuttings Up
Now that some of the cuttings have started to make root you will have to start to think about potting them up in to individual pots. The best type of pot I find as I grow a lot of cuttings is the 4 inch square pots as they take up less room in the greenhouses. The first cuttings always take the longest to root as the days are short. When the cuttings have rooted they are knocked out of the pot. I pot them up in a compost mixture of half multipurpose compost and half horticultural grit sand the grit sand helps to keep the compost open and allow some weight to the pot so the pot will not dry out to quickly, and the roots should be stronger If you do the mix this way when you finally plant out in to the open ground the plant will get away more quickly than if you just plant them in multipurpose compost with no grit in this way you will find that the plants root are soft and fibrous and will be slow to get away in the open ground. Separate the rooted cuttings from each other trying not to knock to much compost of them then half fill the pot, take the cutting by holding the main two pair of leaves try and hold it in the centre of the pot place the compost around the cutting trying not to break any of the roots as this will knock the plant back until it makes more root. Gently firm around the cutting then give it a good drink. At this stage donít forget to put the label in the pot, if you donít you will get mixed up with all the different types and you will have to wait until it flowers before you can name it. Then place the pot in a cool shady part of the greenhouse for a day or two until the plant gets established. Do not water the pot until it starts to dry out, if you give them too much water at this stage you will find that the small roots will start to rot. If the weather is fairly sunny it will be advisable to put some newspaper over them just to take the bite out of the sun. Continue to take cuttings until you have the amount you require. As time goes on keep potting the cuttings up to build up a stock. As the greenhouse starts to fill up you can move the first lot of plants to a cooler place, the ideal spot is a cold frame to harden them of before they are planted out in the garden. Through the day you can leave the frame tops open slightly to let some air in If we get some cold nights they may have to be covered with an old blanket or carpet to keep the frost of them.
Donít forget to spray for greenfly and the dreaded slugs as they love the lush growth of the dahlia plants tender green leaves.
Dark Leaf Dahlias
Dark leaf dahlias are becoming more and
more popular in the borders of small gardens, as there are more varieties being
introduced, from the tall types down to the very small types.
Take the final cuttings of varieties
that you think you are going to be short of. They will flower this year but they
may be late.
1 Keep a check on the weather man for frost at night.
2 Keep your eyes pealed for predators Slugs, Snails and Greenfly.
3 Your plot must be ready to receive the plants or tubers
4 Make sure you have plenty of canes for when you start to plant your dahlias out.
5 Get stocked up with string to tie the plants to the canes; you will always find that you get the plants all planted out and it will come windy all of a sudden.