Dahlias for Beginners 2014 Season

[Tel]

If you would like to grow dahlias, but would like any advice or guidance. We will only be to glad to help.

[Moonlight]

Thanks Tel, I didn't get my 1st dahlia until 1st March, so very much a beginner. I've been re-reading last years thread, so much happened. As I said elsewhere, time flies when your having fun.

[Cherry]

When should I wake up my dahlias Tel? It was frosty last night, so they must come in from the greenhouse today.

[Tel]

Jan 12, 2014 11:49:56 GMT Cherry said:

When should I wake up my dahlias Tel? It was frosty last night, so they must come in from the greenhouse today.

If you are wanting to take only a few cuttings, Cherry. Next month will be soon enough.

[Cherry]

Thanks Tel.

[Moonlight]

What is the purpose of a double stop?

[Tel]

Moonlight, this is not mine, but it gives you the reason why some growers use double stopping.


Single Stop . Here the middle of the dahlia or growing tip is taken out thus allowing new growth to start from each of the leaf axes. The reason in all plants that we nip out the growing shoot is that this growing shoot produces a growth retardant hormone that slows down or stops the growth of these "side shoots". This method is, I think, the most difficult one to achieve a good flower timing from. The reason is that in some varieties the side shoots take no notice of the growth retardant hormone that the growing point puts out.
A good example of this is Kenora Challenger. This is a variety I must grow as a serious competitor in the Individual Championship classes. The side shoots in this variety start to grow ( depending on size of plant) way before you stop it so the resulting flowering time becomes a bit of a lottery based on the weather etc. The answer with this one then for me is to go back to the time of the cuttings and I don't root any up that are taken before April 10th. If you then compare this with the giant red Bryn Terfell, this variety does not show a sniff of a side shoot until after it is stopped.
You can therefore have a stopping regime where you stop plants say two days apart and be fairly sure that your flowers will be two days apart. You can also vary stopping times by which shoots you chose to grow on. For example, if you are growing a giant and want to grow three shoots up to flower, then stop at three pairs of leaves. This will then allow 6 shoots to grow. You can then take out alternative shoots and end up with 1, 1, 1.
In general then, this is not a good way of stopping because the age of the plant plays such a big part in the ultimate flowering date.
Knock Back . Dave Spencer uses this method which is a slight variation on the method above. What he does is single stop but notes the plants as they are coming into bud. As a very general rule it takes about 24 - 28 days from "Pea Size Bud" to flower, so if his plants are going to flower too early he knocks them back. What this means is cut the flowering stem back one or two leaf joints to let new side shoots come. There will be two come and one will be cut out. I think this adds a few weeks onto the flowering time. Now Dave is the only person to have shown in every National Individual Championship Class since it started in 1984 and he has won it, and features in the top three regularly, so obviously this method is good for him.


Double Stop . This is my favoured method but the only draw back is that the resulting flower has 2 to 3 rows of petals less than a single stop. This is great for Trelyn Kiwi, the Dianes etc. that have tons of petal because often you get better petal lay with less rows. However varieties like Challenger don't look as full bodied as they should after double stopping, in my opinion. The first thing you need for double stopping is a big plant. I start most of my tubers off on Valentines day ( because I love my Dahlias) and find that by the end of April the rooted cuttings are ready for potting on into 5 ½ in pots. By the third week in May, therefore, they are usually good big plants often with the crown bud showing colour. This is round about when I do my first stop. Exact dates depend on which shows I am stopping for and which variety I am stopping. I find Trelyn Kiwi to be about a week behind everything else so this is the first one I do. I grow Trelyn 9 up so I will aim for 12 and then pick out the strongest 9 later. The first stop then, I want to grow 6 shoots so I will perhaps stop the plant at 3 pairs of leaves high. 6 shoots will then grow up. I will plant out at the start of June and by the third week in June I will have 6 very strong shoots perhaps 12 to 18 inches in length ( in the case of the Dianes, these can be 24 inches in length). The next step is, I think, hard to do when you first do it because now is the time to cut nearly all the growth of these plants back to the first pair of leaves on each stem ( thus the 6 shoots now produces the twelve I talked about earlier). When you examine the leaf axes (the bit between the leaf and stem) you will see the very start of a tiny shoot. Usually the size of these new shoots is standard for the particular variety and the same size at this point each year.
Basically then, whatever has happened with the weather and other growing conditions before this date we are now starting again from scratch. Under the ground the root system has been growing to cope with the number of stems on the plant and the size of the plant. Suddenly now there is hardly any plant at all but a marvellous root system, the plant now races away and the new shoots that are produced are marvellous. (I think the term "We Have Lift Off" is very appropriate to the way the plants grow after their second stop). On my very sunny plot I reckon about 60 to 65 days (depending on variety) from this second stop to picking for a show. On the odd occasion when the number of shoots produced after the first stop is not enough, or I don't think they are big enough ( this has happened in the past with Mary's Jomanda that I grow 16 up), I will only cut back to two pairs of leaves on the stronger stems so that on these stems there will be 4 shoots on each stem instead of 2.
There is a quite significant difference in size when you double stop, common sense when you think about it. On a single stop only two flowers at most are growing up together but on the double stop that I have described above there are four growing up together so they are bound to be smaller.
The other consideration is " Overall Flowering Time " or length of the flush. With double stopping and letting four flowers flower together they are " Flowered Out" quite quickly but you have more to chose from at any one time ( hopefully this will be the same time as a show). You don't of course have to let all four flower, you can make sure that there are at least twice as many shoots as needed and take alternative shoots out so that only two are growing up at one time and the flush will then be longer also.
In conclusion I would just like to say that I don't believe there is a right or wrong way of growing dahlias. We all do things differently and in ways that suit us. It is certain that our wonderful dahlia responds to all sorts of ways of cultivation and always seems to reward us with a wealth of colourful good blooms, unfortunately not always on the right day. So we just keep trying different things until it all comes right, as it did for me this last year.

[Moonlight]

Jan 27, 2014 8:19:35 GMT Tel said:

Moonlight, this is not mine, but it gives you the reason why some growers use double stopping.

There is a quite significant difference in size when you double stop, common sense when you think about it. On a single stop only two flowers at most are growing up together but on the double stop that I have described above there are four growing up together so they are bound to be smaller.
The other consideration is " Overall Flowering Time " or length of the flush. With double stopping and letting four flowers flower together they are " Flowered Out" quite quickly but you have more to chose from at any one time ( hopefully this will be the same time as a show). You don't of course have to let all four flower, you can make sure that there are at least twice as many shoots as needed and take alternative shoots out so that only two are growing up at one time and the flush will then be longer also.
In conclusion I would just like to say that I don't believe there is a right or wrong way of growing dahlias. We all do things differently and in ways that suit us. It is certain that our wonderful dahlia responds to all sorts of ways of cultivation and always seems to reward us with a wealth of colourful good blooms, unfortunately not always on the right day. So we just keep trying different things until it all comes right, as it did for me this last year.

I am going to grow Tisa which on the Halls website is unclassified, it says on  the website that it requires a double stop.
I was wondering that if it was left alone, would it naturally develop bigger and therefore being showable as a large pom. (As it is unclassified) Obviously a beginners simplified perception but if a stop makes a flower smaller, if you left it alone would the flower naturally be larger? If the dahlia naturally grows larger shouldn't it be left alone and grown and shown as a large pom?

[snute2008]

Moonlight, my understanding would be that for showing the bloom would still need to be the correct size for a large pom, I suppose if you were showing in a local village show that might be different. Double stops are sometimes the only way to obtain the correct size bloom.

[Moonlight]

Jan 27, 2014 12:22:54 GMT snute2008 said:

Moonlight, my understanding would be that for showing the bloom would still need to be the correct size for a large pom, I suppose if you were showing in a local village show that might be different. Double stops are sometimes the only way to obtain the correct size bloom.

I agree - I wouldn't ever consider showing a dahlia in the wrong sized class. I don't think that it matters where a dahlia is exhibited, local or national, if it is the wrong size it is the wrong size and should have NAS - disqualified whatever the correct terminology.

I had a Weston Pirate which was really good, measured it at home with my rings and was fine but when measured at the show it went over size - so was a NAS which was the right assessment.

Unintentionally controversially I think that the variety bloom classification should be used as a guide not as a forgone assessment, if a dahlia is stunning and entered in a class because it is the correct size but disqualified because the official size category is different to the size in the classification, then again unintentionally controversially I think that the rule book is wrong.

I don't think it is fair that some dahlias have duel classification when other varieties are not allowed to be. If the form of the dahlia is perfect for the category and placed in the correct sized class, then it should be a fair entry.

But I'm a beginner, I don't know what I am talking about but in my head it seems wrong.

PS I hope that I haven't gone off on a tangent, at the moment, I'm going to with the flow and see what Tisa grows up to without forcing it. As it is not yet restricted by size classification, if it is a good pom size and it is good enough to enter in a show and if it is good large pom size then I will enter it in the large pom class.

[snute2008]

I believe that an unclassified dahlia cannot be disqualified if it is oversize as it has no classification to be sized against.

[Moonlight]

Jan 27, 2014 13:21:14 GMT snute2008 said:

I believe that an unclassified dahlia cannot be disqualified if it is oversize as it has no classification to be sized against.

That's what I thought.

[Tel]

Jan 27, 2014 13:21:14 GMT snute2008 said:

I believe that an unclassified dahlia cannot be disqualified if it is oversize as it has no classification to be sized against.

If what you is saying is correct, what would the judge do ? if the judge cannot N.A.S the exhibit for been oversize in the class it was entered for, say entered in the Pom class. would the judge not give it a prize and leave a note saying because it was oversize, it should have been entered in the Large pom class.

[Moonlight]

My understanding is that, if an unclassified pom was entered in a pom class and it was too big it was be nas.
If an entry is too big for the rings of whatever size class then it would be nas - the unclassified part is irrelevant.

[richardr]

Controversial Advice from Which? magazine

Which? gave Don't Buy ratings to all the peat-free composts that they tried See report in The Independent

We have had numerous customers that have bought rooted cuttings from us managing to kill them off within a week or so of receiving them by potting them on using low cost, multi-purpose composts and then over watering them.

So, if you are new to growing dahlias beware of the the type of composts you use as they are not necessarily good for the young, delicate recently rooted cuttings.

We advise our customers against them.