Friend or Foe - What's Growing In Your Garden?

May 27, 2022

Identifying seeds from weeds


What’s growing in my Garden?

A common question we see new and old gardeners asking is how to identify their sown seeds from all the other mysterious plants that sprout in the garden. This is not always straightforward, as every garden has their own unique ‘’seed bank’’ in their soil. A seed bank is just that, a bank of dormant seeds that occur in the garden or even your pot plants and can contain a myriad of seeds including annual weeds, grass seed, vegetable & flower seeds.

Many seeds end up in your soil from weeds that have gone to seed. Weed seeds are dispersed via flowering weeds in the garden that drop their seed or are brought into the garden by other methods. Contaminated soil mix, straw and mulches can introduce new weeds, as can bird droppings, manures or even the wind. Other seeds such as flowers and veggies are more likely to come from your spent crops, homemade composts and worm castings. Thankfully, your packet seeds are not a source of weeds in the garden as they pass through strict quarantine measures off the farm to guarantee purity. Packet seed is easily identified and specific to the variety and generally uniform in appearance (unless of course you are sowing a flower mix).  

So what does a seed bank have to do with sowing your Mr Fothergill’s seeds? A seedbank will mean that each time you cultivate, sow and water your packet seeds everything in the soil or seed bank has the ideal conditions to germinate. We often are asked ‘’how did weeds grow in exactly the same place where I sowed my seeds?’’ and this is why. Weeds are a result of your soil practices and they are excellent at covering over freshly cultivated soil, especially when you are regularly watering and caring for the soil. This can do a couple things, it can smother your sown seeds and shade them out which means they don’t grow or it could mean that you have to play detective to find out what is friend and what is foe.

Tips & Tricks

  • Many of the Mr Fothergill’s seed packets show an image of the seedling that emerges from your specific crop of flower. This is useful as when your seeds first germinate they will have a set of intial leaves called cotyledons that actually look very different from the mature crop. Once the plant matures, the cotyledons shed off to make way for the true leaves of your plant. 

    Seedling images on back of packets

  • Get to know your crops a little more. Plants from the same genus will have a very similar appearance in cotyledon and seedling stage. For example, Broccoli, Cabbage, Cauliflower and Kale are all members of the Brassica family and have the same two first leaves. The seedlings almost look like little butterflies or two hearts.

    Here are a few examples of common cotyledons found in the home garden.

    examples of cotyledons

  • Trick the seed bank into germinating before you are ready to plant. This method is great if you have freshly opened up a new patch of soil in the garden. The idea is to water the freshly disturbed soil to encourage seed bank germination. Once all of the tiny sprouts appear cover it over with a black tarp to bake them in the sun. This will help to exhaust the top layer of your seed bank so when you are ready to plant there will be less competition with your desired crop.
  • Use a quick to germinate crop and sprinkle it in with your seeds to identify the rows. This will give you a chance to weed in between your rows before the weeds have taken over. Commonly radish is used for this purpose, dropped in at intervals along your carrot seeds as they emerge in only a few days.
  • Grow a cover crop before your planting season. This is similar to encouraging the seed bank to germinate however, instead of tarping with plastic you are shading out the weeds with a fast growing cover crop that can be chopped back into the soil to increase the fertility.
  • Remove flower heads off weeds before adding them into compost or drown them in a bucket of water to reduce the spread of seeds in your garden.
  • Always use reputable soil & mulch suppliers and don’t accept free fill for your garden if you don’t know the source. They can contain thousands of seeds (including potentially noxious species that will overtake the garden) and even nasty materials including asbestos.
  • In exceptionally weedy soils you will have more luck sowing seeds into fresh potting mix or jiffy pellets as these are sterile products (free from other seeds). You can then transplant them out as seedlings so they have a head start. This is especially helpful for those teeny tiny flower seeds such as lobelia, petunia & foxglove that are easily smothered.


It is helpful to remember if you are ever unsure, there is a wealth of knowledge online in garden forums that will help you to identify the plants sprouting up in the garden. There are also some clever apps for mobile phones these days such as Google lens, which will scan photos for you and deliver a search result. If you are ever stuck with your Mr Fothergill’s seeds send through a photo using our customer service form or live chat and we would be more than happy to identify for you.

Happy Gardening!

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