Weed roots

(Question)

How far in the soil can the roots of weeds grow? I’ve dug about one foot and found roots. I’ve pulled them out…some grew horizontally long and others grew vertically long. The latter were the most  challenging to pluck out…I had to dig deeper until I got deep enough to take them out. For the entire spring and summer we’ve only had weeds growing in the backyard. Before that, we used to grow tomatoes and beans. I’m pretty sure I took out the vegetable roots. Any help would be great, thank you!

(Answer)

A weed is simply a plant that is growing where you don’t want it to. Different plants have different root structures and depths to which they grow. Some will grow laterally and sprout new plants at different nodes on the root. Some will grow shallow roots and some will grow very deep roots. Grasses often have 3-5 foot deep roots and bindweed or Canadian thistle can have roots that in some soils go down 20-30 feet!

The best way to dig out weeds is to do it when they are very small. If you do a lot of digging to remove the weed, you are often just bringing up to the surface new weed seeds that can sprout again into new plants. Small, young weeds are easiest to pull out without too much soil disruption so you might find that removing weeds on a regular basis is the best.

Also, remember that the tops of the plants are where the photosynthesis occurs and where all the plant’s energy is produced. If you are continuously removing the tops, eventually the roots will be so weakened that they will die. So if you have a larger weed, simply cut it at ground level without disturbing the soil. Also try to remove the weeds before they flower and set seeds for next year.

I don’t think that your vegetable roots will have sprouted again into new plants as almost all of them are not perennial and so will die at the end of the season so I wouldn’t worry about making sure you get their roots out at the end of the season. In fact they will just rot in place and provide a little bit of organic material to the soil. It sounds as if you might not have planted anything else in this garden area. Bare soil is often a perfect spot for weed seeds to germinate and grow as there is no competition from other plants so any dormant seeds will have the perfect conditions to sprout and grow. It is, therefore, always advisable to have something growing even if it is just a cover plant like clover or alfalfa.