Is it common for some dahlias to grow slower than others?

12 years ago

I have now 6 dahlias that are supposed to end up being about the same size when full grown, all 4 feet tall except 1 that will be 4.5 feet tall.

But I've noticed that from the time they first started coming up, they are growing at very different rates. I topped every plant just above the 3rd leaf level, the first 2 on the same day, then the 3rd about 6 days later.

Right now, 2 of the first 3 I planted are now about 26 inches and 28 inches tall respectively, but the 3rd is only about 14 inches tall, even though they all came up the same day, are in the same soil, the same amount of sun and water, etc. The 2 larger ones are also much wider.

Then, I started 3 more on June 11(the first 3 were started on May 25), and the ones started on June 11 were again topped at the 3rd leaf level, but on different days because they were growing at different rates. Now it has been about 8-9 days since the first of these latest 3 plants was topped, but its new laterals have only grown about 3-4 inches so far. I topped the other 2 about 2 days apart after the first was topped, and the new laterals seem to be slow, at least at first right now.

I water them at least 2-3 times per week, and they have great soil with nutrients and 6.8 ph.

Is it normal for them to grow at very different rates? Will that effect the time it takes them to start blooming? In other words, will the faster ones bloom earlier?

**Also, Swan Island Dahlias, where I bought the tubers, say that it will take at least 90 days for these dahlias to begin blooming. I've only grown dahlias once before, about 2006, and they were of the same variety bought at Lowes(no name), but I planted them on May 10, 2006, and by June 15, they were about 12-14 inches tall, and they now started producing flowers. They were a taller variety of around 40-48 inches, with white and lilac colored blooms about 4-5 inches in diameter, and almost as thick. I didnt do any topping or pruning of these 3 plants, but they bloomed from June 15 through the end of October almost non-stop!

That means it only took 36 days for this type to bloom, so why should it take at least 90 days for most or all other dahlias that grow around 4-5 feet tall and produce mid sized flowers of 4-7 inches diameter to bloom? Will they grow to maximum height and then bloom, or start blooming while still growing like my others did?

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Comments (2)

redmond_phyllis
12 years ago
Dahlia heights are not precision. A plant that is put in the ground in mid June can quickly catch up to one planted in mid May. I planted one last July and it was blooming one month later, and I couldn't believe how fast it developed. I started one in the garage this year in March, and just NOW it's started to sprout (and I sincerely doubt it will do anything, but it's rare/old and I don't want to lose it.) I have never relied on a grower saying that a plant will be a certain size.
honnat
12 years ago
My experience tells me that 1) dahlias are very different in their growth habits 2) Height is unpredictable 3) Bloom times are very different. It all depends on the varieties you are growing. Generally speaking, larger blooms take a longer time to develop; and cactus varieties generally bloom quicker. But even that is not a science.
As far as plant height - I planted all mine within about 3 days; and now have some plants just peaking out of the ground; and others with buds!!
I'm dabbling in exhibiting dahlias this year and have tried to read everything under the sun about how to time out dahlias for shows. I haven't found any solid way to predict yet. The best advice that I have learned is to just grow a variety and take really good notes (planting dates, topping dates, first bud, first bloom, # of leaf pairs you left when you topped, # of leaf pairs from bottom of plant to bloom etc, etc,....) My wife makes fun of my excel spreadsheet dedicated to my dahlia plants. There is a payoff - If you grow the same varieties the next year you can plan when to plant, when to top etc. I'm following more of a plan this year according to some of the varieties I planted last year (i.e - if it took 57 days for a plant to bloom after I topped it; I know that I should top that variety about 57 days before the show)
That's probably more info than you needed unless you really want your dahlias to bloom at a certain time.
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