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 degrees Celsius in a fairly light place, then you can leave them for a week or so. They will start to take root, as they take root they will be coming back to life you will see that they will be 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 too wet. Some varieties send a thick shoot up first let this shoot get to about a inch and a half long then cut it off with a sharp knife just below the first two leaves. You can throw 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.
As the tubers start into growth and the shoot start to appear you must keep your eyes open for the predators (Green Fly and Slugs) they can soon make a meal of the tiny shoots. I find for the green fly that any of the systemic insecticides will do the trick.
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. 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.
Taking cuttings
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. Don’t 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 it’s 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
There’s 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 variety’s 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 variety’s in all different colours and the Lillyput types Red, Yellow, Pink, Orange Bronze and Purple. These variety’s 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. That’s 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 René Rotaveltts from just outside of Amsterdam. They are small patio dahlias of eight variety’s 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 (don’t 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 don’t 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 don’t 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 don’t forget to put the label in the pot, if you don’t 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.
Don’t forget to spray for greenfly and the dreaded slugs as they love the lush growth of thedahlia 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.
In the tall types you have, Bishop of Llandaff with (red flower), David Howard with (orange flowers), Moonfire with (yellow/red flowers), Fascination with (purple flowers), Englehart Matadore with (purple flowers), and one that I introduced two years ago Summer Nights a single (yellow flowers with a dark cushion centre) and unusual dark bronze foliage.
The small types that grow to about 15 inches and less are very popular you do not have to stake them, are Roxy a single with (purple flowers), Ecentrique semi double with (purple flowers), Bednall Beauty semi double with (velvety red flowers) the stems on this variety turn a lovely bright red when they get wet, Topmix Mama this is a (red single flower) the size of 2 pence peace 12 inches in height looks good in a bed.
Then there is one smaller still Jewel Lila purple flower size of 2 pence peace 9 inches in height very good in tubs.
The beauty of growing dark leaf dahlias are two fold, as the plant is growing you get the lovely dark foliage all summer, then half way through summer you get the bright flowers that set the foliage of even more. Every one knows Bishop of Llandaff, but as far as I am concerned one named Tally Hoe grows about the same height as Bishop is better, its bright orange red single flowers stand proud on the plant.
This flower has also a slight perfumed smell with it, so well worth growing. Then the small growing type Bednall Beauty is a must grow.
Grenadier a bright red almost double flower has lovely foliage, and this variety is much sort after.
The top selling dahlia for us last year was Moonfire and a close second was one that we introduced from Holland two years ago, Ecentrique grows about 15 inches tall.
Some new ones to look out for is the Pathfinder Collection red, orange, purple, and lilac.
To be introduced by J R G DAHLIAS.
And there are a new dark leaf dahlias from Holland just out, The Bishop Collection, I am growing for the first time.
If you didn’t start your tubers up early in compost, to get them to shoot now is the time to be planting them out in the garden. If we have any frost now it will not be hard enough to damage them as long as they are covered over with soil, plant about six inches deep.
Don’t forget to keep your eyes open for slugs spray with Slugit all over the ground.
Almost There
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.
They will also provide stock for next year, you can grow them on in pots sunk into the ground (Keep them in pots all summer), as they come into flower check the flower to make sure that you have the correct label in the pot then take the flower of and keep doing this and you will make a nice plump pot tuber for your next years stock.
Continue to pot up the rooted cuttings.
Move on the older potted plants into the cold frame to acclimatise them to cooler conditions ready for planting out the first week in June, I usually start to plant out about 6th June by that time all fear of the dreaded frost will have past.
Don’t forget to cover the frames up at night with fleece or old carpets just in case we do have some frost.
The plants should be fully acclimatised to the open ground conditions by the end of the month.
If you don’t need a large number of plants, you can start to plant your tubers out in the open ground the middle of May by the time they have popped through the ground surface all danger of frost should have gone, but if the ground is warm the shoots may appear early, so you must keep your eyes open for them peeping through and cover them at night with a bucket or large pot this will protect them.
Tubers will generally flower sooner than a cutting.
Don’t forget to spray for greenfly with systemic insecticides and the dreaded slugs with Slugit as they love the lush growth of thedahlia plants tender green leaves. As you plant your tubers you can scatter some 6x concentrated manure around the tubers or sprinkle some grow more general fertilizer around them, this will give them a good start in life.
News Flash from the N.D.S A.G.M Northern Meeting, a big step forward for some of you show men and judges, there are going to be some changes in the National Dahlia Society, New Classified Directory for 2005 they are going to change some types of dahlias that are classified as Decorative type to Ball type and visa versa as the N.D.S say they are loosing to many good dahlias that can not compete with the likes of Ruskin Diane family, for some of you that still may remember the Hornsey family and Rothsey Robin varieties we may be going to seeing some more of that type on the show benches.
It is all down to the petal formation some decorative types are very close to being a ball type.
This may mean we will have another classification added to the book.
This must be good for the dahlia and for the raiser; I personally will look forward to seeing more and more different dahlias on the show bench instead of all yellows.
To find out more about your favourite flower join your local dahlia society or the national one and get two bulletins a year with lots of useful information with all the show winners from around the country.
1 Keep a checkon 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.
JRG Dahlias 