Rooted Dahlia Cuttings: How To: Part 1
I know that I’ve written on this before but I’ve learned a lot through the years and wanted to share an updated tutorial of sorts on taking dahlia cuttings.
This is Part 1:
To begin: You are going to need a few things-
1. Grow lights- You can use ordinary shop lights. I suggest one warm and one cool bulb to get a broader spectrum of light. You can also buy actual grow lights (I’ve gotten affordable ones through Sunco recently). But unless you are taking these cuttings during a time of year where you can do it outside, you’ll need lights of some form.
2. Rooting medium and containers. You’ll need some sort of container to root your cutting into- I suggest getting some plug trays. The container doesn’t need to be really big, in fact it’s better if it’s not. It would take a long time for the cutting to fill up a 4-5” pot. So a plug tray that’s an inch or two in plug size is ideal. Greenhouse Megastore has great options.
Rooting medium can be many things and I suggest trying them all if you are brand new to this. Some people like a good quality potting soil, some go into straight perlite, or even sand. Some people like a custom mix of all three. I’ve even seen people use a small vase of water. Personally I like a potting soil mix that is heavy on compost and peat. This holds water well. You don’t want your media to dry out too fast.
3. Right conditions: You’ll need somewhere that can be kept between 65-70 degrees. You can use a heat mat under your cuttings. You can put them in a room with additional heat. You are looking for the soil temperature to be in this range.
You’ll also need humidity. Remember the cutting has no roots at first so you have to keep it moist so it won’t wilt. You need to keep the humidity high enough for it to not wilt while it’s forming it’s new roots.
4. Patience- Yes, this activity requires a bit of patience and perseverance. There’s a good likelihood that the first ones you try- some won’t work. 100% success rate almost never happens. We usually have about 5-10% of each full try fail or just take so long to root that we toss them before they can. So remember that this is a process of figuring out how to get the right conditions for your cuttings because everybody’s set up is different- You just have to keep tweaking it.
Other helpful things:
1. Rooting Hormone- dahlias will root without it. But you can speed up the process and get faster and more vigorous root growth with it. Pretty much any kind of rooting hormone will work. I like Hormodin 3- this has a high concentration of IBA- Indol-3-butyric acid. Hormodin 1 and 2 will work just as well but 3 has a higher percentage of IBA. Now you can get too much IBA, however, the amount contained in Hormodin 3 doesn’t run into those too high numbers.
2. A fan- if you are using a grow room set up, a fan is a great idea to promote air movement which keeps powdery mildew down and can help with fungus gnat control
3. Mosquito bits- Soak these in a gallon of water and then water your cuttings with it- this will help kill the larvae of fungus gnats. You can also buy Gnatrol (but it’s expensive). The mosquito bits do the same thing.
4. Labels- We use vinyl blinds written on with pencil— these don’t fade and they are cheap!
Last but definitely not least: You are going to need some tubers to propagate from. So go grab some tubers out of winter storage and join me back here next week and we will get started on the actual process of taking a successful dahlia cutting!
