You raked your seedbed smooth and sowed it with seeds for your cut flower garden. You water it and wait, and a week later, the seedbed is covered in tiny green sprouts. But there are a lot more sprouts than there should be. And they don’t all look the same. Your seedbed has become a weedbed.
One of the big pitfalls of direct sowing has struck. You now have to figure out how to tell the difference between the flower seeds you planted on purpose and the weed seeds that snuck in while you weren’t looking. But how?
Distinguish between flower seedlings and weeds by using methods to make the weeds stand out, such as planting in rows or learning what the flower leaves look like. You can avoid the issue altogether by sowing into a sterile seed-starting mix and transplanting the seedlings instead of direct sowing.
There’s no magic answer here, but a couple of straightforward tips will make the identification game much easier.
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How do I know if it’s a flower or a weed seedling?
The best answer here is that experience will help you tell the difference between a weed and an intentionally-planted flower seed. But until you get there, there are a few handy tips to help you figure it out:
1. Plant seeds in a row to make the weeds stand out
One of the easiest ways to identify weed seedlings is to make them stand out by planting your flower seeds in rows. More than likely, anything that sprouts outside of the row is a weed.
When sowing your seeds, you can either eyeball it, or you can use two stakes with twine tied between them to get a razor-straight line for your flowers. As a side benefit, the straighter the planting row, the easier it is to set up drip irrigation. Two birds with one stone, right?
One or two exceptions would be if you know you dropped a few seeds while planting or heavy rainfall between the sowing and germination of the seeds. The rain could have washed some seeds outside of the row, in which case you’ll have to use one of the other methods to get ahead of the weed game.
2. Look out for speedy sprouts. They’re probably weeds
Since the mother plant dropped weed seeds, they’re in the soil before your flower seeds, just waiting for the suitable soil and weather conditions to sprout. They’re also already adapted to your yard’s micro-climate since they are second-generation (or more!) plants.
The result is that weed seeds will almost always sprout before your flower seeds, especially when they start getting their share of the irrigation and compost meant to pamper your flower seeds.
In addition to speedy weed seeds, just knowing the time your flower seeds need to germinate will help tell the difference between the two types of sprouts.
Most annual flower seeds need between 5-14 days to sprout under the right conditions. I don’t know any weed seed that will wait two whole weeks to sprout when they’re getting regular watering and access to sunlight.
So when I see green sprouts break the soil’s surface after just a week, I know it can’t yet be my flowers—time to hoe them down and wait for the real deal.
3. Get to know the true leaves of your favorite flowers
The most reliable method also takes the most time to learn. Just knowing what the leaves of your flower plants look like compared to the leaves of common weeds will give you an advantage.
When flowers sprout, they all start out with their first set of leaves, called the cotyledons. These leaves will fuel the seed through germination until it can make food through photosynthesis. These leaves are usually unremarkable and can easily be mistaken for weed seeds.
However, after just a couple of weeks, annual flower seedlings will have grown their first set of true leaves, which are the type of leaves that the flower will continue to grow for the rest of its life. These leaves tend to be much more identifiable through their color, texture, veins, and shape.
To truly get the drop on weed seedlings, learn to recognize what your flower seedlings look like, and dealing with weed seedlings will become a quick task.
To help you get started, check out this comprehensive guide to flower seedling identification from The Seed Site. Use the search bar to look for the flower you want to see, and it should be the first result.
Skip seed-or-weed confusion by transplanting seedlings
If you want to make your life easier, just start seeds indoors. You won’t have the pressure of learning to tell the difference between a flower and a weed seedling right away. The only answer will be “weed” when all your flower seeds are tucked up in a seed tray inside.
Just be sure to start with a sterile, store-bought seed starting mix rather than garden dirt. Otherwise, you’ll just be bringing those weed seeds inside, and you’ll be right back where you started.
If you’re new to starting seeds, check out this resource: Step-By-Step Guide To Starting Seeds Indoors (Plus a sample setup).
If you prefer a video, check out this tutorial from Danielle of Northlawn Flower Farm.
Once you get busy sowing your flower seeds, check out this post, I Planted Too Many Seeds. Now What? just in case you get carried away and need some more how-to.