We all know that this has been an incredibly HOT summer. But nothing tells the story of too much heat better than a “hardy” perennial garden chrysanthemum (mum). Garden mums suffer from too much heat by displaying a condition known as heat delay. Simply stated, mums do not like temperatures much above 85 degrees and as they mature, they need to cool down to temperatures closer to 75 degrees. Once the flower buds start to show color, 65 degrees, even down to 60 is best. (Sounds a lot like fall)
During a normal summer in Fort Wayne temperatures usually average around 85 to 86 and never go into the 90’s for more than just a couple of times all season. Garden mums therefore are normally only delayed for just a few days, which isn’t very noticeable. With temperatures in the 90’s almost every day for over a month, heat delays are prominent and visible everywhere you look. I have been to Wal-mart, Lowe’s and Scott’s/Kroger stores and what I am seeing are mums barely showing color at this time when normally they are almost “bloomed-out.”
Buying and planting garden mums while they are so tight is really the best stage for transplanting into your flower beds and will also ensure long lasting beauty right into the late fall season. Having mums on the tight side is only bad if you needed them for instant color such as for a party, a wedding or an open house. Getting your mums planted early in the season also guarantees a good root system by getting your mums established before a hard frost or freeze.
After planting your mums, watering is a must for a couple of weeks while they get established in the ground. Fertilizer is not so important as they were fertilized all summer long during their growing period. After they are budded and showing color, fertilizer is reduced or eliminated all together. Remember, cool weather is what they really like. Even frost will not harm them so more than likely you will have blooms this year into November.