Germination…

I decided to plant a small patch of wild flower mix that came from the Prince of Wales’s garden at Highgrove. I thought that the back of this rockery that already has some Iris and Cowslips would be the ideal location. I killed off the weeds with some glyphosphate weed-killer, raked the soil to create a nice tilth and then pressed the soil flat to make a suitable surface for the seeds. Then I sprinkled seeds over about two square metres of the soil and once again walked over it to press the seeds gently into the surface.

That little patch of soil above is now sown with a wild mix of grasses and flowers that might look quite nice in a couple of years. The seeds will need to germinate and establish firm roots if they are to compete with the host of other plants that will naturally appear in the garden. Hopefully, with a little love and attention, my choice of plants will dominate the area and keep competitors at bay by sheer weight of numbers. We will see!

I used glyphosphate weed-killer to clear the area first so that the seeds I sowed had no immediate competition. Glyphosphate is rather clever stuff in that it kills most grasses and broad-leaved plants on contact with the leaves but it is quickly broken down on contact with the soil so it won’t affect germinating seeds. It is one of the most widely used herbicides in the world. It became hugely popular when glyphosphate resistant crops were genetically engineered. This meant that farmers could spray the whole field with glyphosphate whilst the crop was growing to kill all the weeds but leave their crop unharmed. As a result of its very heavy use, some weeds are developing natural resistance to glyphosphate and new herbicides are having to be found to combat these resistant weeds.

Questions…

1. What three conditions are necessary for seeds to germinate?
2. How can you tell that Selfheal is insect pollinated?
3. Plants distribute their seeds to avoid competition. Suggest something for which plants compete.
4. Suggest a function performed by a plant’s roots.
5. What are the raw materials needed for photosynthesis?
6. Why do plants tend to have many small leaves rather than a few large ones?
7. [Harder] Glyphosphate is a compound of carbon, hydrogen, oxygen, nitrogen and phosphorous. From the picture, can you work out its chemical formula?