Pruning is the removal of vegetative parts (stems, leaves) of a plant. It is usually done to increase productivity, improve appearance, ensure plant health, and/or facilitate harvesting.
- Tools (scissors, knives, etc.) must be cleaned and sprayed with a 70% alcohol solution (rubbing alcohol) before being used. Hands must also be washed if a diseased plant has been touched.
- If cutting can be done near a budding region or a leaf joint, make sure you cut close to the bud while leaving it intact on the plant, as plants tend to heal rapidly there.
- For better healing, pruning should be done at a 45° angle through the stem (a beveled cut).
- When trying to limit the expansion of the plant, cut only the top third of a stalk (the third of the length starting from the tip) or of the plant, in the case of naturally dense plants like chives.
Plants to prune, and why
- All crops : You definitely want to remove any yellowing or diseases leaves or fruits from any plant.
- Tomatoes : We’ve covered that elsewhere in great details.
- Cucumbers and squash : We’ve covered that somewhere else.
- Tomatillo and ground cherry : Both crops are of the same genus (Physalis) and can get very bushy. Prune to limit expansion of the plants if desired. Cutting out branches will reduce the harvest, which is rarely limited if the plants are growing in proper conditions.
- Eggplant : For large-fruit varieties, some people suggest keeping 5-6 fruits per plant to avoid breaking the stem.
- Sunflower : Some varieties produce many flower heads, which can become too heavy and break the stem. You may want to remove some flower heads in that case.
- Herbs & flowers : Topping some herbs and flowering plants can result in a bushier and more productive plant, or in more flowers.
- Fruit bushes, trees, etc. : Most woody plants will need pruning at some point or another. Raspberries and blackberries, as a notable example, grow new canes every year, which bear fruits the second year, and then die the third year. For this reason, canes that have borne fruits during the summer should be cut back in late fall or early spring, when the plant is dormant. More information on pruning woody plants can be found here.
Staking and trellising
While not all crops need support to grow vertically, some do benefit from it. Different methods exist, such as staking, trellising, twining, and caging. Plants can be grown vertically to save on horizontal space, for plant health management, for aesthetic reasons, or for general plant management such as facilitating harvest. Vertically grown plants should always be installed on the north side of a garden, where they won’t shade other sun-loving plants.
Plants to grow vertically and why
- Tomatoes : Covered in another article on this blog.
- Cucumbers and squash : Covered in greater details right here.
- Peas : To facilitate harvest and for health management, peas are usually grown vertically. They are, after all, climbing plants. Install a trellis of at least 4 feet high next to the peas. Training them to grow on the trellis might be necessary at first, after which the plants may climb their way up on their own.
- Pole beans : Beans exist in two varieties, bush beans and pole beans. Bush beans do not need support and can be grown anywhere that is very sunny. Pole beans are usually grown up a piece of twine, a trellis, a pole, or a teepee of poles (see image below). Note that some varieties can grow up to 10 feet during a single season.