End of Season Dahlia Checklist
It’s time to begin your end of season tasks. Yes- I know they really just got going good, but some of these tasks you need to do now!
So to prep your dahlias successfully for over winter and next year:
1. Make sure they are labeled properly. Double check every plant and make sure it’s tag reads the correct variety. I use old vinyl blinds (the cheap kind), cut them up and write on them in pencil. It has never failed me! If you are digging your dahlias, zip tie it to the base of the plant.
If you have a mislabel that you can’t identify, try posting in Dahlia forums on Facebook, asking friends, check with the supplier- there are multiple ways to figure it out. And if I can’t find the actual name, I just write a description- that way I know it’s not what the original label said it was.
2. Figure out when you need to stop fertilizing. Look up your average first frost date and then work back a month from there. After that point, don’t fertilize any more. You don’t want to encourage a lot of new growth towards the end of the season. Just let your dahlias focus on tuber growth during the last month. If you don’t wait until frost to dig your tubers, just stop fertilizing about a month out from when you will dig.
3. Decide on your winter storage method. We’ll talk more in depth about this later but decide if you are going to dig or leave your tubers in the ground.
4. Make your wish list for next year. Decide who you want to add and who’s getting the boot to make room for new additions.
Where are they now?
Today it’s the dahlia version of “Where are they now?” I decided to share updates on the varieties that I’ve written about in the past and how they fared in the extreme heat/drought of 2024’s summer.
Last fall I released a list of 5 varieties that really stood out to me as being potential great cut flower varieties. But in 2024, I’ve seen some different results (this is why I grow a variety minimum 3 years before I’ll add it to my “must grow list for the hot South.”)
1. All That Jazz- well I’ve yet to see a bloom, they are barely at bud stage. The plants are small and have struggled despite being in a slightly cooler spot than a lot of other varieties. We’ll see if this one gets to stay.
2. Cryfield Harmony- Can’t speak to this one b/c as I said last year- it’s a great cut flower— For cool weather growers. So hopefully some of you tried it out!
3. Caitlyn’s Joy, Copper Boy, and Tahoma Curve- I’m grouping these because they’ve all done excellent. Tahoma had a bit of spider mite damage but pulled through it well. I’ll continue to keep these in my collection.
4. KA Mocha Katie was also a special mention and it has done exceptionally well. Got attacked by spider mites but just keep right on growing and has been a steady producer for weeks now.
Below are all the photos of these varieties:
Out of Your Control
One unintended benefit of writing a newsletter that goes out across the country is that I can tell by the number and the content of the emails I get what kind of year it’s been for growing dahlias.
And this year- it’s been rough! I don’t always follow the weather across the country but I do know that the extreme heat/drought in July that a large majority of us experienced was brutal and caused a lot of loss.
Hamilton Lillian
At the end of July I walked around my field with a clipboard. I took notes on every variety- I figured it would be a good time to see who’s really heat tolerant. But what I kept seeing over and over again- was the phrase: “xyz caused by extreme heat”- insert spider mites, powdery mildew, etc- whatever was the case for you.
At first I was really bummed and very frustrated. I knew my dahlias were almost a month behind where they should have been. But then I realized something….
We had been consistent. We fertilized when we should have, we controlled pests when they attacked, we removed old leaves to allow air flow, we netted on time. To be honest, we got it really right this year.
But the weather had other plans- And nothing we could have done would have changed that. We did everything we could have and should have but at the end of the day- the weather is out of our control.
So I took a few days and accepted it. I adjusted my mindset and realized that we are going to have a killer season once we get to mid- September. The dahlias are just going to be a little later this year. But on the plus side- October weddings are going to be gorgeous!!
What if you are new to growing and didn’t know to fertilize, control pests, etc? Well- it’s not too late. Fertlize them soon. Look around on this blog- there’s lots of info about bug control, fertilization and general dahlia growing knowledge. It will still make a difference for this season.
So if you are frustrated - hang in there. It’s going to get better. The weather is already getting better. Fertilize, water, control your pests and be patient a little longer. The blooms are coming!!
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**You may have noticed I said “we” a lot in this post. I couldn’t have done it this year without my incredible team. There is absolutely no way the dahlias would still be alive without them. They are amazing- Sophie, Nonah, and Josie- You ladies are the best!!
Hapet Champagne
Water Water Everywhere!
It’s hurricane season here in the south and most of the coastline is bombarded by rain at the moment. But what does that mean for your garden and your dahlias?
After growing dahlias through almost 10 hurricane seasons, you pick up a thing or two so here’s what I do to prep my fields for nasty weather.
Holly Hill Black Beauty
I live in the Upstate of SC so not quite the crazy of a full blown hurricane up here. But we do get tropical storms occasionally. (I honestly hate those b/c if were are getting a tropical storm I know my coastal friends are getting slammed with a category 3+ Hurricane. There’s not much you can do in that case.) So really this is advice to get through nasty thunderstorms and high wind.
Preparation is key. It starts from the day you plant your dahlias. Good drainage is your best friend in a heavy rainfall and high wind situation. But you have to plan for it from day 1. If you missed the boat on that this year- go make a note to fix it next Spring. You want your drainage at the level where 6-8” of water will drain off within 24 hours. Dahlias can take sitting in water for that long- it’s not great for them but they’ll make it.
Support- You will probably need extra. We use hortnova netting to support our dahlias. These nasty storms are why we use 2 layers on everything but the shortest varieties. We also went around the field with paracord and used this to tie up any dahlias that were growing outside the netting- they like to try to escape. Paracord works better than twine- paracord tightens up when it gets wet so less droopiness.
Remove the Yuck- Removing the lower leaves on your dahlias in hot climates is a common practice to increase airflow but not always possible when you grow 1000’s. But this has been such a rough summer with the extreme heat that we made time for it. Leaving all the old yellowed foliage on during a heavy rain event is going to cause some fungal problems later on down the road. Most years we only do this as needed but occasionally we have to do the whole field.
Remove the blooms. Blooms that are over the main canopy of your plants are top heavy and are going to catch in the wind and cause your whole plant to sway more from side to side- therefore pulling at the roots unnecessarily. So we remove any blooms above the main plant canopy.
These tips will help protect against major losses in my experience. I saw a question on Facebook the other day and it reminded me of a similar incident that happened to me many years ago. The poster was asking: “Should they try to dig their dahlias to save the tubers after all the rain came through?” It appeared they didn’t have a great drainage situation and were worried about rot.
I had a portion of my field (that is now fixed thankfully) that had very poor drainage. It was mid October and we got loads of rain- standing water of several inches in between the rows. I was really worried about my plants rotting. So since it was almost the end of the season, I cut them back and dug them up. I thought I was being very clever and saving my tubers— WRONG! Removing saturated tubers from the ground is not the right thing to do. There really is something to the process of letting tubers “cure” a bit in the ground before digging. This requires drier soil (not bone dry) but soil with an average amount of moisture. Any year where we’ve had a wet period before we begin digging- I noticed we had increased storage issues during the winter. Years where we get just a bit of rainfall- they tubers always store much better. The amount of water a tuber holds going into storage makes a difference. I don’t know of any scientific studies on it or even how to measure it. But the basis of all good science is observation and observing over many years has taught me to pay attention to the moisture levels in my soil during digging season.
Moral of the story here is — Prepare ahead of time because in this time of crazy weather patterns you never know what’s going to come and I’ve never been sorry that I over-prepared!
Why Soil Tests Are Important?
I’m not sure what it is, but for a significant portion of us there seems to be one thing we overlook in our beginning gardening years: the soil test! I will admit I was guilty of it too- I think I was a few years into my veggie garden until I got one. In fact— I think it was taking the Master Gardener Certification Class that finally kicked me into gear to get one.
So that said- Today I’d like to talk about why soil tests are so important with a few anecdotes from my farming/gardening experience.
To begin we are going to talk about sweet peas- my favorite crop after dahlias. I’ve had an issue with bud drop (stems suddenly losing every bud they have) every year since I started growing sweet peas. Some people say this is environmental, some say it’s nutritional. I was talking to an experienced farmer friend this past spring and he suggested getting a soil test done and then having a custom fertilizer blend made just for the sweet pea crop area.
What a great idea I thought! I contacted a fertilizer company who makes custom blends (Seven Springs Farm Supply) and asked what they needed. They just told me to get a soil test and then call them to discuss what my goals were for the crop.
So off to the Sweet Pea Palace (as we call that tunnel) I go and I gather my soil, put in a bag and mail it off to my local extension service (Clemson University) and then I wait. About a week later I got the results back.
And to be honest, I was a bit disappointed. I was actually hoping the soil was going to be deficient in something. Because solving the bud drop issue in sweet peas from a nutritional standpoint would be a whole lot easier than a climate issue.
But as you can see from the above picture, the soil is great! Boron is an element that is suggested to help with bud drop but there’s no issue with that in my soil.
So back to the drawing board on solving my problem— BUT do you see how the soil test helped me? It helped me eliminate a solution. It also saved me money on fertilizer that I didn’t need. It also tells me that most likely I don’t need to add anything to this soil this fall. I will test it again in September before we plant. But as long as we monitor the elements in the sufficient range from year to year, we don’t need a lot of the typical fertilizer elements you would apply.
Now let’s take a look at a plot of soil over the course of 8 years.
The first soil test I can find for my farm is from Fall of 2016. We moved here in Fall of 2015 but you know how moving goes- I probably forgot to take one when I began.
What you see here is pretty typical for soils in my region. Acidic and high in Potassium and Phosphorus and reasonably sufficient in other elements. It’s clay soil - heavy but rich.
Let’s skip ahead 2 years. This is 2018- same area of soil on the farm.
One noticeable change is the pH- it has gone way up to 7.1 which is actually a little high for what I want. So we used elemental sulphur to bring the pH into a more neutral range. You can also see that the majority of the primary nutrient levels have increased.
In the early years of our farm, we used compost made by our pigs. And it’s great stuff— but it’s rich— richer than our clay soil rich! So after seeing excessive levels for a few years, we backed off of adding the pig compost and any extra potassium and phosphorus.
The cation exchange capacity more than doubled too. If you want more info on what this is- click here. Clemson’s site can explain it way better than I can.
Skipping forward to 2021:
So you can see that we were able to lower the pH level— which changing pH can take some time and it’s a good idea to not make huge adjustments in it quickly.
But the biggest difference is the potassium level is much lower. In fact on all the soil tests we took in 2021- most of them showed a lower potassium level, some even showed that we needed to add. This is a good illustration of how long it can take for a nutrient to adjust in your soil.
Building good soil is a continuous process. You need to have goals but they will change as your soil adjusts.
Skipping forward one more year to 2022:
So what’s different? Well the pH went back up. My guess is because we gave that tunnel a good dose of compost. One thing we work on in our soil is organic matter. Organic matter greatly improves clay soil We don’t always need tons of nutrients because clay soils are usually rich but we need as much organic matter as we can get! So adding compost is something we do on a regular basis. Every year? Nope— too expensive to do the whole farm but we rotate around so that every area gets it every 2-3 years. That decision is crop dependent as well. Adding compost raises your pH level.
The potassium levels have risen- we added muriate of potash. This was in rock salt form and I was able to find it at my local feed and seed.
So what’s the lesson here: Taking regular soil tests gives you so much information to make decisions over time. You can really get to know the soil in a certain area. I’m sure an agronomist could have all kinds of fun with these. That’s way out of my skillset but you don’t have to be a soil scientist to read a basic soil test.
Few other things:
1. These are basic soil tests- there are labs where you can get more in-depth analysis done. You can also pay a bit more on these basic ones and find out your organic matter percentage and the nitrate nitrogen levels (we did this for the Sweet Pea test up top).
2. Where you sending your soil test? Begin by googling your local extension service or your state’s best ag university. Or you can send it to Clemson- they will test out of state soil.
3. How often should I take a soil test? Yearly at a minimum. If you are monitoring a change you are making in your soil then I would say every 6 months. Or take one when you need the answer to a question like I did for the sweet peas.
4. If you have a large area of land, take multiple. Divide up your areas and test them separately. We test all our hoop houses separately and then test a few areas in our main field.
5. How do I take a soil test? Go here— Good directions from Clemson. It’s super easy!!
I really hope I’ve convinced you to get a soil test this fall. Fall is a great time to get a soil test done because you can apply any amendments you need and they will do their work over the winter and your Spring soil will be so much better!
So— go put it on your calendar for some time in September to take a soil test!!