Petunias are must-have plants known for their large and vibrant flowers. They look particularly stunning in containers and add a wonderful pop of color to container gardens. Unfortunately, petunias rarely stay as vibrant and lush as the day you bought them, particularly if you don’t maintain them correctly.
Leggy petunias are an incredibly common problem. As you hit the middle of the season, the bushy mounding shape starts to trail, spreading out and looking sparse. Lack of sunlight or incorrect care, particularly when it comes to watering, can also cause plants to become lanky.
Luckily, you don’t have to live with sad, lanky container plants forever. With these five solutions, you can get them back to looking their best in no time.
Prune
No matter the cause of your leggy petunias, the first step to fixing them to is cut back. Pruning now won’t only resolve the stretching stems, but regular maintenance will also stop the stems from becoming lanky again in the future.
Petunias naturally trail and spread as they grow. If you want to maintain compact growth and a mounding rather than sparse habit, prune back the foliage every couple of weeks to keep them looking lush. Pruning also promotes branching to create a fuller plant with more flowers – the ultimate goal.
When you’re ready to prune, grab a clean and sharp pair of pruning shears. You can pinch the tips of younger plants with your fingers, but it’s best to use high-quality garden tools to avoid potential damage to the stems. Sanitizing is vital to prevent the spread of potential diseases, particularly if you pruned any diseased plants recently.
Cut back the elongated shoots just above a node, removing the stretched sections completely. Make sure there are several leaves remaining on the bottom section of the stem to keep the plant alive. While they can handle heavy pruning, you don’t want to cut back too much, as this can slow recovery.
After this initial pruning, trim the shoots every few weeks, removing under an inch of stem to stimulate new growth.
Deadhead
These famous flowering ornamentals produce masses of blooms throughout the summer. Although this is one of the reasons we love them, it also means more maintenance. To resolve and prevent leggy petunias, regular deadheading is essential.
Spent flowers not only impact the overall look of the plant, but they also draw valuable resources that could be used to fuel new growth and flowers. The production of seeds also takes priority over leaf and stem development, causing the spindly vines we are trying to avoid.
Whenever you spot a flower that is fading, pinch it off the plant to encourage new shoots. If any seed pods are visible, also remove those, leaving only a few toward the end of the season if you want to collect them. You can pinch them off with your fingers or use a pair of pruning shears.
Deadheading may not seem like a high-priority maintenance task, but it’s one of the best ways to prevent elongated stems and keep your plants blooming continuously throughout the season.
Increase Sunlight
Although less common, lack of sunlight can cause the stems to become spindly. If the sunlight levels are not ideal for healthy expansion, the plant will respond by seeking out more sunlight. The stems stretch toward the nearest light source, resulting in leggy growth.
It’s easier to identify this cause by the direction of the stems. If they are all reaching toward one side where the light is strongest, lack of sun is the likely cause. You’ll also notice few flowers because these plants struggle to bloom in shade.
For containers, the solution is simple – move the pot. Trimming back and moving the plant to a brighter area will provide the right environment for strong performance. If the light source is strongest on one side, it’s also helpful to rotate the pot every now and then to stop one side from becoming lanky.
If your petunias are planted in the shade, you’ll need to move them to a position with at least six hours of direct sunlight to improve their appearance and vigor. It’s far better to start by planting in the right position than having to move your plants later on.
Fertilize
Nutrition is important to consider for all petunias, particularly petunias that are becoming leggy. This is a common problem for potted petunias, as the consistent watering required to keep them happy also leaches essential nutrients from the soil.
If you haven’t adopted a regular feeding schedule, now is the time to start. I recommend feeding regularly with a mild liquid fertilizer with a balanced NPK every few weeks, providing easily accessible nutrients that will prevent an unsightly appearance.
There is a key caveat to this point. Too much fertilizer can also cause spindly growth. Excess nitrogen can cause stems to become elongated at the expense of flowers. It’s not as common for potted plants but may occur in beds if your soil already has an excess of nitrogen.
The answer to the problem is to fertilize regularly, but not too much. Always follow the instructions on the packaging and never feed more often than required, especially if your plant appears stressed. Excess fertilizer at this time will only make the problems worse.
Water Consistently
The final solution for leggy petunias is to keep up with the watering, particularly in summer and when the plant is flowering.
Petunias love moisture, and allowing the soil to dry out too much can lead to stress that results in spindly stems and weak growth. If the leaves are wilting and yellowing and flowers die off quickly along with elongated shoots, you likely need to adjust your watering routine.
Potted petunias need watering almost daily in summer to maintain consistent soil moisture. It’s vital to keep an eye on temperatures and water more often during hot weather to stop the soil from drying out completely.
Another important element of watering is consistency. Don’t forget to water for one week and then water daily the next week, as this will cause further stress. Once you find the right balance of soil moisture based on your variety and planting position, water at this rate consistently to prevent further leggy growth.
