There are two types of plants known as forget-me-not. One is an annual and is the true form and one is a perennial and more commonly known as false forget-me-not. They both have a very similar appearance but are in different genera. Should forget-me-nots be divided? This really depends upon what variety you are growing. If your plant comes up every year in the same spot, it is likely a perennial; but if the plant seems to migrate and multiply in other areas, it is the self-seeding annual.
When to Split Forget-Me-Nots
Many perennials benefit greatly from division. Dividing forget-me-nots can help the plant form stouter stems that are less floppy and prevent center die out. It can also increase the number of plants or control the size of an existing plant. In the annual form, forget-me-not will readily self-sow, populating the garden in every nook and cranny over time. Perennial forget-me-not flower division is recommended for the above reasons.
Since the annual form will reseed itself and then die out, it does not require plant division.
The annual plant has hairy leaves, while the perennial has a glossy leaf. Annual forget-me-not flower division is not necessary, but the glossy leaved perennial will benefit from division every few years.
How to Divide Forget-Me-Nots
Perennial types. Perennial plants will develop less flowers over time, even though the plant will expand in size. This is how you know when to split perennial forget-me-nots. If flowering is suffering, division can help create healthier plants that bloom more. Dividing forget-me-nots every 3 to 5 years can help prevent this problem while it also makes more plants.
Dig around the root zone carefully in early spring and gently lift the entire plant. You can actually divide the plant by hand, separating out sections with numerous roots and several healthy stems. Each group should be planted individually. Select a location in full sun with well-draining soil and water in each plant thoroughly.
Annual types. You don’t need to worry about how to divide forget-me-nots that are the annual, hairy-leaved form. They will merrily drop seeds and wind will spread them to likely locations of the garden. You can collect the seeds and sow them in loose garden soil in full sun after all danger of frost has passed. Cover seeds with a light dusting of soil.
Keep the area moderately moist if spring rains are not sufficient. Thin out plants to prevent overcrowding; however, they actually thrive when tightly packed together. Transplanting forget-me-nots is not recommended, so plan carefully where you want these charming little blue flowering annuals.
Just remember, in a couple of years the entire garden plot may be taken over in spring by plants whose name says it all.