Content

• Steps
• Method 1 of 2: Know When to Prune
• Method 2 of 2: Pruning sunflowers
• Tips
• Warnings

Annual sunflowers (plants that only bloom once) generally don't need pruning. However, sunflowers that grow in clusters may need to be pruned so they don't jam on top of each other. In comparison, perennial sunflower varieties sometimes require pruning. Pruning helps these plants maintain a neat and tidy appearance during the summer months, when they tend to be rebellious. To prune your plants correctly, you must first know when to prune them.

Steps

Method 1 of 2: Know When to Prune

1. 1 Prune perennials twice a year. A good general rule of thumb for pruning perennial sunflowers is to trim them in half in late spring or early summer. Then, reduce their size again by a third in June or July.
2. 2 Remember the warm climate. Gardeners in warmer climates should prune marsh sunflower (Helianthus angustifolius), which has willow-like leaves (Helianthus salicifolius) about two-thirds of its original height in June.
   • This procedure will keep these potential giants in a more manageable size and eliminate the need to support them.
3. 3 Avoid pruning after the first flowers appear. Most perennial sunflower species bloom between mid and late summer. In such cases, growers should keep an eye on their plants and refrain from pruning after bud formation.
   • However, the rules are slightly different for late summer flowering varieties. Species that bloom in late summer should be cut when they reach a height of 0.45-0.6 meters, because they will recover in a few weeks and bloom regardless of the cut.
4. 4 Prune very tall sunflower varieties in June or July. Maximilian sunflowers (Helianthus maximiliani) and Mexican sunflowers (Tithonia diversifolia) should be pruned in June or July. This will reduce the size of the sunflowers from their typical height of 2.7 meters or more to a much more manageable 1.2 meters.
   • Maximilian sunflowers can also be left standing during the winter months as food for birds. If you choose to keep your tall sunflowers for the birds, they can be cut to the ground in early spring to prepare the plant for new growth.
5. 5 Be aware that annual flowers will not bloom again. Annual sunflowers can be cut to the ground when they begin to dry out and turn brown. They will not bloom again, which is why many gardeners choose to remove them from their gardens entirely.

Method 2 of 2: Pruning sunflowers

1. 1 Pre-sterilize all trimming equipment. Sterilizing pruning equipment is especially important if you have recently dealt with diseased plant parts. This will prevent bacteria or germs from inadvertently spreading throughout the garden.
   • Prune sunflowers with a sharp, sliding-blade hand pruner or hedging scissors.
2. 2 Trim unhealthy parts of the plant first. Prune diseased, weak, damaged, braided or dead branches from the plant before starting any kind of heavy pruning operation.
   • The diseased parts should not be in the compost to prevent the doubtful disease from being passed on to any other plant. Instead, these pieces of trash should be burned or left in bags for local waste collection crews.
3. 3 Prune perennials so they get the shape you want. After you have cut off any unhealthy branches, you can prune your perennial sunflowers for shape.
   • Some people choose to trim only the damaged parts of the plant, so the sunflowers can take on a wilder appearance.
4. 4 Water your plants after pruning. Water your sunflowers regularly after pruning to help them recover from stress. Give them enough water to thoroughly saturate the soil every time the top 2.54 cm of soil becomes dry.

Tips

• After the gardeners have done the pruning, they should oil the gardening tools to prevent them from rusting. Gardening equipment should be stowed away in a safe place so that it can be easily found again for later use.
• Cutting off the top buds of these plants with scissors is a very effective method of reducing plant height. Although the side buds will form flowers, the plants will not get the same growth.

Warnings

• Gardeners need to be careful when going to prune their plants because annual sunflowers that are pruned will not produce new flowers.