Growing Dahlias From Seed
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Thank you for your purchase of our Dahlia Seeds!
Dahlia seeds are a fun way to explore the world of dahlias, grow something new and beautiful and maybe create your very own dahlia cultivars!
Dahlia seeds are much different than tubers, in that each seed has it's own unique set of genetics. That means each flower that is grown from a seed will be different. No two dahlia seeds are the same, and that makes growing dahlias from seed limitless.
Here is your step by step guide to ensure you successfully grow your dahlias from seed.
So first and foremost, dahlias are not cold hardy plants. They will die if they freeze and so because of this, it is generally recommended to start your seeds indoors, 6-8 weeks prior to your last frost date. This gives the seeds a head start on growing prior to when most people plant their tubers.
If you are unsure of when your last frost date is, you can find the approximate last frost by zone here.
If you are not sure which hardiness zone you're in, that same link contains a map that will show you by legend which zone you are in. It is important to know which hardiness zone you're in when growing flowers because each zone has its own 'rules' when it comes to direct sowing and transplanting.
So now that you've done the math and figured out when the last frost is for your zone, you've counted back 6-8 weeks from then, it's time to actually get your hands dirty and get your seeds planted.
Note: Dahlia seeds can tend to have poor germination rates. We suggest using the paper towel method when germinating seeds.
The first thing you will need is the proper tools for your seed starting.
You will need the following to get your seeds started:
- A growing medium such as seed starter mix or potting soil etc.
- Seed starting tray
- Water
- Light Source
- Temperature
Growing Medium
Seed starting mix: there are a ton of starting mixes on the market. Some vary in price, and some seem to shell out some big promises when it comes to germination and growth. The truth is, when a seed is starting to grow, all the nutrients it needs are within the seed. Meaning that the seed does not take on any of the nutrients that are within the soil for the first couple weeks of growing.
Seed starting mixes generally contain peat moss, vermiculite, or perilite or a combination of all three. They are super fine in texture, and retain moisture without letting the seedling get too water saturated.
The thing to remember though, is when you're using a seed starting mix, you will need to transplant the seedling to a medium that contains nutrients once the first set of true leaves have grown. That is because the seedling is no longer relying on the seed itself for nutrients, but now needing to source it from the medium in which it's planted in.
Seed Starting Tray
Just like the growing medium, there are a ton of different vessels to start seeds in. The main thing to keep in mind is that whatever you grow in needs to have drainage, or else the seed will rot. It doesn't take much for a tiny seed to rot in too much water.
There are specialty seedling trays that contain a lower tray to keep water in, and another tray that fits inside, that has a bunch of seed cells to start multiple seeds.
Seed Cubes/jiffy pellets are another alternative to starting seeds. They are little pods that are geneally made from peat moss or coconut coir. They self contain the seeds, and contain the growing medium they need, so two birds, one stone.
If you don't want to purchase specialty seedling trays, literally any cup, tray, pot, plastic bowl and everything in between will work. You just have to ensure that you can poke or drill holes in the bottom so that your seedlings don't end up oversaturated with water.
Ive also seen people make their own seedling pots out of newspaper. This can be a great environmental option as no plastic is being used. Check out a newspaper seedling pot tutorial here.
In addition to needing a container to grow the seed in, you will need a plastic cover for germination. The plastic cover will have to go over the entirety of the container, to create moisture and humidity in order for germination to take place. I have also included another method of germination at the bottom of this article.
Germination can happen anywhere from 2 - 10 days. Dahlias don't all germinate at the same time, and if your space is colder than they like, it can take longer.
Water
I think it should go without saying, that your seedlings will need water. In fact, this is a crucial step in ensuring your dahlias will grow into seedlings. When you are planting dahlia seeds, make sure that the growing medium you are using is well saturated without being soaked. I mist the seedlings trays to keep them moist but not over saturated. If the seed trays/ cells dry out, the seedlings will not grow, if the trays get too wet, you run the risk of your seedlings rotting and moulding.
Light Source
Like all plants, dahlia seedlings need light.
Many growers start their dahlias under grow lights to mimic the sun, but have more control over the amount of light the seedlings get. Many professionals will leave the light on their dahlia seedlings for 14-16 hours. Any more time than that can be a detriment to the seedling.
As far as the type of lights needed to grow your seedlings indoors, you can use specific grow lights, but most people have had success using a fairly basic full spectrum LED shop light.
Here is the link for the lights I purchased here.
Temperature
Dahlias need a fairly specific temperature for germination. Ideally between 18° - 21° C for best results. If you are growing in a space that is cold, you will need to supplement with a heat source. A heat mat is the perfect way to achieve a consistent temperature for your dahlia seedlings. You want to ensure your mat will automatically shut off when the correct temperature is reached.
** Paper towel method for germination**
As mentioned above, there is also another method for the germination of your dahlia seeds. The paper towel method, is simply to take 2 paper towels and wet them with water. Do not completely saturate the paper towel. It cant be sopping wet, just damp. A spray bottle can be helpful for this. Lay the dahlia seeds on the paper towel, with some space in between so you can keep an eye on them. Fold the second paper towel over the first to create a little "bed" for them. Put them in a plastic bag and seal the bag. Dahlia seeds do not need light to germinate. Check them at 3 days and continue to check daily. Once you see sprouts, transplant them into their seed cubes or trays.
I hope this article gives you enough insight to starting dahlia seeds. It may seem daunting at first, but as with growing most anything, if you follow the steps and insert a bit of intuition, there is absolutely no reason you cannot have beautiful dahlia seedlings of your own.
If you have any questions at all about starting seeds please email me at Terri@sweetvalleyflowers.com and I'd be happy to help you out wherever I can.