Annuals Not Producing Flowers

Many people get caught up in springtime and begin planting flowers and plants around their homes or in their gardens and watch them bloom. Flowers, especially, are a favorite and annuals contain many of our favorite flower varieties.

Some people, though, find that they can purchase seeds or starters from the greenhouse or garden store and then they get lush plants growing, but no flowers or blooms. Why is that? Here are some ideas that may be the reason that annuals are not producing flowers.

Too Much Nitrogen in Soil

The primary cause is nearly always too much nitrogen in the soil. In our haste to make the plants beautiful, we got overzealous with the fertilizer or used a mix that was too nitrogen rich. With annuals, good potting soil to start the year is probably all they’ll ever need – anything more than a little fertilizer at the very beginning is just overkill and may lead to problems later.

The only exception to this no-fertilizer rule are container plants in light soil or soil substitutes. They will likely need liquid fertilizer every couple of weeks to keep them beautiful. Think of these container systems as hydroponics rather than traditional soil plantings and you’ll stay on track.

So with annuals, you generally don’t fertilize beyond the initial planting. The effects of too much nitrogen are many, but the primary thing you’ll notice is that the plant grows quickly and gets very leafy and green. It fills out with its foliage and puts little or no effort into buds and flowers. With flowering plants for decoration, of course, that’s obviously not the goal. A big, lush plant is great, but if it doesn’t flower you don’t get the benefits of flowering plants.

Another problem is that all of this leaf growth means that the nitrogen is stimulating energy production and takes the proteins that make them grow. The down side to this is that all of this growth and leafing out wastes energy and is replacing energy and nutrients that would be used for other aspects of the plant’s development. Most notably with internal health. Like a human that eats too much sugar, too much nitrogen in plants leads to a weak immune system and the likelihood that the plant will become infested by bacteria, fungus, or bugs.

To negate over-nitrogenated soil, first check the soil’s acidity. If the pH is high or low (acidic or alkaline), adjust the levels to a balance it. This allows the plant to more easily take up phosphorous (P) and potassium (K). In acidic soil, the phosphorous binds with other minerals and makes itself unavailable to plants and in alkaline soil, both the phosphorous and potassium can be washed away by water or lost to aeration and into the atmosphere.

Another option is to fertilize with a heavier or all-PK mix. Organic options include greensand (P), seaweed (P), guano (K), fish meal (K), or bone meal (K). The good news is that of the three vital nutrients to plants (N-P-K), only nitrogen can become too much. The others are so hard to take up and so easily absorbed by surrounding materials in the soil that plants will almost never overdose on them.

Obviously, using a good, rounded, well-made compost is the primary way to get the nutrient levels in your soil just right.

Want to learn more about annuals not blooming?

See these helpful websites:
Growing Annual Flowers from North Carolina Cooperative Extension.
Annual Flowers: A PDF from Purdue University Cooperative Extension Service.