Black-eyed susan
#1
what do you do to prepare these for winter?do you need to save and plant any part for new flowers next year? Or can I just cut them back to the ground?
#2
If this is the true "black-eyed Susan" (Rudbeckia hirta) they are short-lived perennials and may persist for some years if cut back after bloom, but more likely they will bloom once from seeds dropped in late summer which means you can't cut them back. The gardening world is just full of contradictions like this.
You can just let them self sow. The seeds will ripen and drop to the soil. Leave the plants alone until just before snowfall and then cut down to about 1"-2" above the soil line. New seedlings should emerge in the spring. If the plant itself is going to return you will know its location by the location stubs left behind after cutting back.
If this is one of the new hybrids, hybrids will not come true from seed and will probably need to be planted new next spring. You will know soon enough if the plants are going to come back on their own in time to plant new if required. Even the hybrids tend to be short lived.
You can just let them self sow. The seeds will ripen and drop to the soil. Leave the plants alone until just before snowfall and then cut down to about 1"-2" above the soil line. New seedlings should emerge in the spring. If the plant itself is going to return you will know its location by the location stubs left behind after cutting back.
If this is one of the new hybrids, hybrids will not come true from seed and will probably need to be planted new next spring. You will know soon enough if the plants are going to come back on their own in time to plant new if required. Even the hybrids tend to be short lived.