MIRABILIS JALAPA (Four O'Clock Plant) They say is a Perennial

[roadrunner]

I have many of these plants, because it's so good at reseeding itself; when I first acquired them, by accident (seeds in a batch of mulch I collected), they were only in one section of my yard, now years later they're all over the place.

I like the plant for the flowers and the hawk moth it attracts, but the major problem I have is that it seems to die very quickly after flowering, probably only survives a month after flower and then it stops and its foliage begins to turn yellow and the plant wilts away.

How is this plant a perennial?

I understand it is native to places just a little south of me and can't survive the winters here; however, this issue of it dying is well before any change in temperatures. Although if I do cut the plant down it will re-emerge from its huge potato-like tuber.

Curious of others experience with this plant.

 

[alp]

Some perennial plants shed their leaves in winter for example, Dicentra and yet they come back the following year almost without fail. Yet, if the soil is too soggy or too hot, the root might rot and you will have to buy a new one. As explained here

Bleeding hearts ... all undergo a dormancy period sometime during their growing cycle.The dormant period, when above-ground growth turns yellow and dies back, varies with the species of bleeding heart and with the growing conditions.

They are dormant, but they are alive. Sometimes, an annual can live through the winter if given optimal conditions. I had some cascading lobelias which lived through the whole winter and flowered very early the following spring whilst the newly sown seeds were struggling to germinate.

 

[MaryMary]

roadrunner, do you deadhead the flowers? If not, then start!! They only want to spread a ton of seeds, and then their job is done. They'll bloom over and over, all summer, just deadhead them.

As far as perennial, I have heard that they are, but well, you know... Ohio.

Four o'clock survives in the ground with a good protective winter covering in hardiness zones 8 and 9. To winterize the plant, water the soil deeply enough to saturate the tubers before the first frost in autumn. Clip off dry and dead growth to within 3 inches of ground level after the ground freezes, then cover the plant with 4 to 5 inches of mulch such as straw, pine needles or dry, chopped leaves. Avoid using wet leaves as mulch, as the leaves become compacted and prevent water and air from reaching the tubers. Remove the mulch as soon as shoots poke through it in the spring. https://www.gardenguides.com/info_8196946_four-oclocks-perennials.html

Four o’clocks grown in zones 7-11 need very little help to survive the winter because, although the plant dies down, the tubers remain snug and warm underground. However, if you live in zones 7-9, a layer of mulch or straw provides a little extra protection in case of an unexpected cold snap. The thicker the layer, the better the protection.
https://www.gardeningknowhow.com/ornamental/flowers/four-oclocks/winterizing-four-oclocks.htm

Do you mulch them for the winter?

 

[roadrunner]

I don't deadhead anything, because it's just too much work, but especially too much work with this plant, because it just has way too many flowers. It's quicker to just chop and drop the whole plant into the mulch. I just find it strange how the plant just dies after it's done with it's relatively short (albeit intense) flowering period.

I have two other plants that also flower crazy, but they don't die after flowering. One is the Spanish Needle, which produces tons of flowers in the spring and as summer approaches it slows way down and sends all its energy into growth and then starts up flowering again in the fall, before dying off in the winter.

The second is the Square Stem plant, which seems to grow and flower all year, until this time of year when it starts dying -- I just cut down a 7 ft specimen which has been growing/flowering all year and now there's new growth coming up -- nice plant.

So I'm just not sure why they call them perennials, unless it's because they grow back from the root system if you cut it down and I think if the plant is mature the root system may survive over the winter, not that it really matters, because there are so many seeds there will be seedlings in the spring.

Spanish Needle:https: //www.motherearthnews.com/natural-health/herbal-remedies/herbalist-spanish-needles-ze0z1402zjhar

Snow Square Stem: https://fnps.org/plants/plant/melanthera-nivea

I mulch every thing in the winter, this is the time of year that I take my pickup and pick up leaves and other yard waste from various neighborhoods. BTW, a lesson learned here is when picking up yard waste, stay away from not-so-nice neighborhoods, unless you don't mind sifting trash out of the leaves

 

[Upsy Daisy]

Mine flowered all summer and well into autumn, but I do deadhead... ...everything . I bin them when they're done and sow collected seeds in ear!y spring.