How Often to Water Mums for Vibrant, Long-Lasting Blooms All Season

Chrysanthemums, commonly referred to as mums, are the hero of the fall garden. These blooms add autumnal color to porch steps, backyard patios, gardens, and other areas of the landscape from late summer through fall. One way to ensure your mums last until (and maybe even beyond) the first frost is knowing how often to water them. Mums watering needs change throughout the growing season, needing more during early September and less when fall officially arrives. To guarantee your mums stay prolific throughout fall, we spoke to horticulturists who shared their best watering tips.

The Best Time to Water Mums

Aim to water mums first thing in the morning before it gets too warm. According to Linda Langelo, horticulture specialist at Colorado State University, cooler temperatures allow the mums to absorb water better. "This also gives the water a chance to drain down into the soil before the heat of the day, when some of the water becomes lost to evaporation," she says. Watering mums at night can increase humidity and moisture levels, resulting in fungal issues.

How Often to Water Mums

Generally, mums need 1 inch of water per week during the growing season. While they can tolerate only being watered during prolonged periods of dry weather, mums grow best when they're watered regularly, says Justin Hancock, horticulturist for Costa Farms. The best way to gauge if your mums need a drink is to feel the soil and water when the top 2 inches are dry to the touch.

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Factors to Consider

How often you water mums depends on several factors, such as soil quality, temperature, and container size. Here are some things experts say to consider when watering mums.

Sunlight

Mums need at least six hours of full sun daily, meaning they can dry out quickly. "The brighter the spot, the faster the mums grow and use water," says Hancock. "So, if you have a potted mum and you’re going out for summer vacation, moving it to a shaded spot may help it hold up longer while you’re not around to water it."

Temperature

Similarly, mums need more water the hotter it is outside. "The warmer the weather, the faster mums typically use water, and the more moisture is lost to evaporation," says Hancock. On the flip side, mums usually won't need as much water when it is cooler outside.

Container Size

How big or small the container your mums are in plays a role in how often they need water. "The larger the pot, the more material there is to hold moisture for the roots, and the less frequent watering you may need to do," says Hancock. "The smaller the pot, the faster it will dry out." However, he notes that the container shouldn’t be so large that your mums stay wet.

Soil Quality

The type of soil you have greatly dictates how often your mums need water. For example, Langelo says mums need more water in sandy soil because it has bigger spaces between the soil particles, allowing water to move through it more freely. Clay soils and organic-rich soils are more dense and need less frequent watering.

Mulch

You may need to water less often if the soil around your mums is topped with mulch. According to Langelo, mulch can mitigate moisture loss because it keeps the soil cool by preventing hot afternoon sun from shining directly on the soil.

How to Water Mums

The best way to water mums is by watering around the base of the soil with a garden hose. Keep the foliage dry as you water to prevent diseases and reduce water loss to evaporation, says Hancock. If you're growing mums in containers and the soil is very dry, Hancock recommends soaking the container in a large bucket of water for about an hour to rehydrate it.

Signs of Overwatering

Mums don't like having wet feet, which can cause yellowing or browning leaves and stunted growth, says Langelo. The foliage may also become soft and limp, and you may experience a foul smell from the soil. Yellowing leaves typically occur on older foliage first, as it takes time for disease to set in, Hancock adds.

Signs of Underwatering

The symptoms of underwatering often present similarly to overwatering, so it can be hard to discern the difference. "Yellowing and browning leaves and stunted growth are common for both underwatering and overwatering," says Langelo.

Luckily, there are ways to tell the two conditions apart. Cracked soil is common with underwatering, and the foliage may take on a dull gray-green tone. "As underwatering continues, the leaves may start to wilt or droop, then drop, Hancock notes.