Growing mums in Pennsylvania can transform your garden into a colorful autumn paradise. These hardy flowers bring vibrant hues just when other plants start fading away.
With Pennsylvania’s distinct seasons, knowing exactly when to plant your mums makes all the difference between short-lived displays and gorgeous, long-lasting blooms.
1. Spring Planting Window
Late April to early May offers the perfect planting opportunity for garden mums in Pennsylvania. The soil has warmed enough after winter, but summer’s intense heat hasn’t arrived yet.
Spring-planted mums establish strong root systems before blooming season. They’ll have months to develop before fall, resulting in bushier plants with more flowers.
2. Late Summer Advantage
Mid-August through early September works wonderfully for adding instant color to Pennsylvania gardens. During this period, nurseries stock pre-budded mums ready to burst into bloom.
The moderate temperatures help plants transition smoothly into your garden. Just remember these late-planted mums might not return next year as reliably as spring-planted ones, since they have less time to establish roots.
3. Avoid Early Fall Planting
Resist the temptation to plant mums after mid-September in Pennsylvania. Plants set out this late rarely survive winter because they can’t develop adequate root systems before freezing temperatures arrive.
If you must buy mums in October, enjoy them as temporary decorations in containers. The energy these plants need for root growth gets diverted to flower production, leaving them vulnerable to Pennsylvania’s cold winters.
4. Consider Your Hardiness Zone
Pennsylvania spans USDA zones 5b through 7a, affecting your planting timeline. Northern counties (zones 5b-6a) should plant earlier in spring and avoid late summer planting altogether.
Southern counties around Philadelphia (zone 7a) enjoy a longer planting window extending into early September. Check your specific county’s hardiness zone for precise timing – those few weeks can make all the difference for winter survival.
5. Watch Local Weather Patterns
Pennsylvania’s weather can be unpredictable, so adjust planting dates based on current conditions. An unusually warm spring means you can plant earlier, while extended cold spells signal waiting a bit longer.
Similarly, extremely hot summers might require delaying late-summer planting until temperatures moderate. Smart gardeners check 10-day forecasts before planting, avoiding periods of extreme heat, drought, or early frost.
6. Perennial vs. Florist Mums
Garden centers sell two types of mums with different planting timelines. True perennial mums should be planted in spring for best winter survival in Pennsylvania gardens.
Florist mums (often sold in fall) rarely survive Pennsylvania winters regardless of planting time. They’re bred for perfect blooms, not hardiness. If buying fall mums, ask specifically for hardy garden varieties if you want them to return next year.
7. Coordinate With Garden Tasks
Time your mum planting around other Pennsylvania garden activities for efficiency. Spring-planted mums can go in while you’re planting other perennials or dividing existing plants.
Late summer is perfect for replacing faded annuals with fresh mums. Many Pennsylvania gardeners use this transition period to refresh beds that have lost their summer color, creating a seamless display through fall.
8. Moon Phase Planting
Some Pennsylvania gardeners swear by planting mums during the waxing moon (between new and full moon). This traditional technique supposedly encourages stronger flowering and root development.
While scientific evidence is limited, many gardeners report success with this method. If you’re planting in spring, try coordinating with April’s or May’s waxing moon phases for a fun experiment in your Pennsylvania garden.
9. Holiday Weekend Planning
Pennsylvania’s holiday weekends often align perfectly with ideal mum planting times. Memorial Day weekend (late May) works wonderfully for spring planting in most parts of the state.
Labor Day weekend typically offers ideal conditions for late-summer planting. These long weekends give you extra time to prepare soil properly and ensure your mums get a stress-free start in your Pennsylvania garden.