Growing Dahlias in pots is probably one of the easiest ways of keeping them safe from pests, although it comes with its fair share of problems. Generally speaking, the main reason why Dahlias tend to die in pots is because they are either being underwatered or overwatered which exposes the tubers to diseases and to tuber rot.
To ensure proper hydration for your dahlias, it is recommended to give them a thorough watering 2 or 3 times a week. However, in hot and dry climates, daily watering may be necessary to keep them adequately hydrated. It’s important to strike a balance and avoid overwatering, as the soil should be moist but not soggy or waterlogged.
Watering the Dahlias in pots should be done twice per week, although in hotter climates this is not nearly enough. Pots tend to dry out relatively quickly, and if you allow the soil in the pots to completely dry out then it will become hard like concrete. It will be extremely hard to rehydrate compacted soil, so try to avoid it as best as you can. If the soil in the pot has compacted and even shrunk, then you will have to water it every day until it loosened up, and most importantly place a thick layer of mulch on it.
On the other hand, if your area has a rainy summer, then watering them twice per week can mean that they are being overwatered. As with everything in life, there should be a balance when it comes to watering the Dahlias in pots. If you want to know how often to water your Dahlias planted in the garden then check out my recent article How Often To Water Dahlias? ( Top 9 Things To Consider ).
How Often To Water Dahlias In Pots
When it comes to watering dahlias in pots, it’s important to strike a balance to prevent both under-watering and over-watering. As a general guideline, potted dahlias typically require more frequent watering compared to those grown in the ground. The frequency of watering depends on various factors such as the size of the pot, the weather conditions, and the moisture retention of the potting mix.
As a starting point, check the moisture level of the potting mix by inserting your finger into the soil up to the first knuckle. If it feels dry, it’s time to water. Aim to keep the potting mix consistently moist, but not waterlogged. Be mindful of hot, dry weather as it may necessitate more frequent watering. Additionally, ensure proper drainage in the pot to avoid waterlogged conditions that can lead to root rot.
When The Topsoil Is Dry
As a general rule, no matter in what kind of pots or in what kind of climate you are growing the Dahlias, you should only water them if the topsoil is dry. Do not wait until the plants start to wilt or get stressed out due to the lack of water, instead put one of your fingers into the topsoil, and if the top inch is dry then it is time to water them. This watering method works not only for Dahlias in pots but even if you plant them directly into the garden.
This way you will only water the Dahlias when they actually need to be watered, as oftentimes a strict schedule can mean that they will get overwatered. Generally speaking, with this method you will be watering your Dahlias from once to up to 3 times per week. If you are worried that you have overwatered your Dahlias then check for these signs ( Top 5 ) Signs Of Overwatering Dahlias.
Dahlias In Plastic Pots Need To Be Watered More Often
Not all pots are created equal, while some tend to hold on to a lot of moisture, but there are others that can overheat extremely fast and all of the water evaporates. Plastic pots are usually a bad idea for Dahlias because these pots absorb a lot of heat. This excess heat will evaporate the water not just from the topsoil, but from the entire pot. As the water evaporates from the plastic pot you will see a clear gap between the soil and the pot.
This happens because the soil actually shrinks and compacts, and at that point, it will become a lot more difficult to water the Dahlias as most of the water will simply run off. If you are growing your Dahlias in the plastic post, then make sure to do the finger test every day. On hot summer days, the Dahlias in plastic pots should be watered either every day or every second day, although with less water.
If you are growing your Dahlias in clay pots then you will only have to water them around twice per week, although make sure to test the topsoil if it is dry before watering them.
Dahlias Should Not Be Watered After Planting
One of the biggest mistakes that most people tend to do when planting their Dahlias is that they immediately start watering them a couple of times per week. This is not necessary as Dahlia tubers have everything they need in order to sprout, and this also includes plenty of water. If you water them before the Dahlias have sprouted then you are only increasing the chance of the tubers rotting. Freshly planted Dahlia tubers can not absorb water, they need to grow roots to be able to absorb water.
When the first couple of leaves emerge then the Dahlia tubers probably already have some roots to absorb water, and at this point, it is safe to water them.
Mulched Dahlias In Pots Have To Be Watered Less Often
The best part about mulching Dahlias is that the mulch will protect the topsoil from drying out. This means that you have to water them less often, as there will be more than enough moisture in the soil for the Dahlias. If you are currently watering your Dahlias 1-3 times per week, and you mulch them, then you will only have to water them once or maybe twice per week. As for what kind of mulches you can use, there are plenty of options, although try to avoid grass clippings as they will attract slugs and snails.
Keep in mind that, even if the potted Dahlias are mulched you should still check if the topsoil is dry to know when to water them. Do not check if the mulch is dry, but when the topsoil is, as oftentimes the mulch will dry out but the soil below it will be still moist, which means that you do not have to water them. If you want to know what are the best mulches for Dahlias then check out my recent article Best Mulch For Dahlias ( Top 9 Mulches ).
Key Takeaways
- Dahlias in pots should be watered 1-3 times per week, although this also depends on the local temperatures and if it has rained in the past week or not. To know when the potted Dahlias need to be watered, stick one of your fingers into the topsoil, and if the top inch is dry then the Dahlias need to be watered. Dahlias potted into plastic pots should be watered more often around 2-5 times per week as plastic pots absorb a lot of heat which means that more water will evaporate from the soil.
- In windy weather, you will have to water the potted Dahlias more often as water tends to evaporate faster in these conditions.
- Make sure to only water the potted Dahlias if the top inch of the topsoil is dry.
