Why My Plants Won’t Bloom (Iris, Peonies, Lilacs, Wisteria, Rose of Sharon, Spring Bulbs - daffodils) It seems like these plants get more questions about why they “don’t” flower, than any others! So, here are a few of the “excuses” we have collected as to why your plants may not be flowering.
Iris - Over crowed and need to be divided (maybe every 3-4 years) late July and August / Too much nitrogen being fed to them (bulb foods are generally lower in N and higher in P and K or even numbers) / Planted too deep / Too shady (need ½ or more sun for foliage and tubers) / Iris borer / disease problems. / Transplant adjustment (re-rooting).
Peonies - Lack of sunlight (need ½ day sun or more) / Recovering from transplanting (sometimes take a few years to re-establish and flower) / Immature plants / Lack of nutrients in the soil / Over feeding with high nitrogen fertilizer / Planted too deep (biggest reason) / Growing conditions previous year not conducive for flower bud formation / Competition with surrounding plants / Lack of moisture / Buds develop but don’t open - frost, disease, drought or too wet.