Hand Weeding Works for Me – Joshua Moats
Hand weeding is probably the oldest form of weed control. It is rarely considered in most Western Canadian farming systems. The biggest problem with hand weeding weeding is that the labour required is expensive and slow. It can also be physically damaging.
My family’s farm does not employ this technique on a large scale, but rather in response to new weeds that are difficult to control by large scale methods. We resorted to hand weeding in response to the invasion of scentless chamomile.
Scentless chamomile is problematic on our farm. It moves down the waterways connecting to Wascana Creek near Regina Saskatchewan, some of which border on our land. It appears first in ditches which are normally dominated by well-established smooth brome grass. Scentless chamomile finds a foothold here despite heavy competition. Normally, the weed spreads from the ditches into wet areas of the field. The water inhibits crop competition and the mud inhibits our machines.
Now established in sloughs it expands into fields, directly competing with the crop. Even after pre-seeding control measures are used, individuals germinate in the crop. It can survive tillage and mowing due to indeterminacy and mud clumping on roots. It is also resistant to post-harvest physical control because it can function as a biennial, winter annual or short-lived perennial. This means that it can germinate after our post-harvest weed control techniques are used, and survive until spring. The infield population is constantly refreshed by the slough/ditch population.
This weed can result in yield losses in its second year of life, in which it is much larger and more difficult to kill.
So far, we have been able to control scentless chamomile, keeping its population below the threshold for yield loss, by selectively hand weeding it in the spring and summer.
Tools are not very effective after the canopy has closed in.
- Gloves – Increases grip, reduces chlorophyll staining of hands.
- Early Days – Keeps you out of the heat.
- Rubber Boots – In the morning, there may be dew on the crop and mud on the ground. I usually bring rubber boots to rectify this problem.
- (Mostly) Dry Conditions – Have to manage dirt clumps on plant roots. Soil clumps can sustain the plant after they have been pulled. Moist soil generally results in a larger clod that sustains the plant for longer.
- Clump Management – In addition to sustaining the plant, if you are going to manage the residue, knocking most of the dirt off the roots makes them easier to manage.
This technique works fairly well. It is difficult to get over the idea of having a clean field. It is virtually impossible pull all the weeds on such a large area. The newly germinated plants begin producing seed too rapidly. It is the second year plants that decrease yield. They also have an exponentially larger biotic potential than the first year plants due to the many more flowers on the plant. When pulling scentless chamomile, you have to remember that you are attempting to reduce the weed below a threshold. That is, you can’t get them all, so get the big ones because they are more problematic. Finding all the newly germinated weeds takes far too long.
We upgraded the technique since we began hand weeding scentless chamomile. In the first year, we packaged the weeds in garbage bags and brought them back to our yard to manage the residue. They take a long time to dry out and this gave them time to escape. Now we have scentless chamomile at home. It is not a big issue because we vigorously mow and rototill our yard for aesthetics but we are very reluctant to bring the weed residue back to our farm. We tried leaving them piled in the field, but these resulted in very weedy patches near the piles next year and an obstacle to equipment. We even attempted to burn them in field by bringing a barrel out to the field. They still took a very long time to dry out.
We have not yet developed an effective technique to deal with the weed residue, but are still trying to find one. If we were to use clear plastic bags for the residue and leave them in field, we might be able to contain them. It would be something like plastic mulch. The sun would heat the bags during the day, hopefully enough to sterilize the seeds while stopping their further spread throughout the field. It could have some potential.
Hand weeding can be effective at controlling new weeds invading an area over small acreage. It is successful, because it is very selective, causing virtually no crop damage. It is limited by the amount of physical labour available and slow speed at which it can be done. I think that this technique is much more commonly applied and effective in smaller high value horticultural operations and gardens than it is in large scale farming.