13,520 Garden Web Discussions | Perennials

Whatever you leave will become mulch. On both of those plants, the stems are not woody at all and decompose quickly enough that they settle down under new spring growth, which completely covers it.

If the lambs ear is the blooming kind (some types are bred not to bloom) the dead flower stalks likely contain a lot of seed. The same is true for catmint. One way I like to propagate both those plants is to shear the stems with some heavy-duty kitchen scissors (or anything else that works) and toss the dead stuff somewhere I want them to grow. Both types are vigorous re-seeding plants that will go from seedling to blooming plant by next summer if they germinate in the fall.

Be careful about composting the stuff because then your compost will erupt into blankets of plants wherever you put it. That's one reason to leave the dead material in place where it can benefit the garden and only multiply in place.

Thanks all!

pizzuti, that's an excellent point and plan.

Thanks all!

Am I the only one that has problems keep SAC alive? I've inadvertently killed several over the years either moving them or just disturbing the roots. And I have never had a seedling. Had to move a small one last fall and potted it up for the winter but it did not grow this year. I am keeping the pot. Maybe it will come next year. I miss the late bloom and fragrance.

The eighty some other clematis I have are all doing well.

I don't think moving it now will be a problem. The new growth should be hardened off and with a good watering in it probably won't even wilt.

If it dies I can send you a couple of the dozens that have seeded out throughout my lawn. There used to be a plant next door which was removed.... the seedlings remain. I'd love to keep a couple and let them grow, but it's so invasive I'd hate to see them seeding out all over the neighborhood.

I know the seeds are quite toxic but I don't know in what concentration. When my son was a preemie infant, he had episodes of frighteningly high heart rate (we once clocked him at 320 bpm in the NICU) called Superventricular Tachycardia, SVT. Anyway, they had him on a medication called Digoxin. The 'dig' part of the drug name comes from Digitalis as that's what the medicine is made from.

The hospital staff put the fear of God into us about how serious this medication was and the importance of NOT OD'ing him on it. They told us that there didn't used to be an antidote so kids had died before from the med. Once, after a particularly difficult night caring for my preemie twins I dosed the wrong twin with digoxin! They were in their baby swings right next to each other and I just gave the med to the wrong baby because I was so out of it (it's difficult to maintain normal function when sleeping in 45 minute increments). Fortunately, it turned out okay because my daughter had never been given a 'loading dose' of the med so the dose for her brother was not enough to have a negative impact. I thought for sure we were going to have to ambulance her to the local children's hospital. It's about as scared as I've ever been.

That said, I DO have a few foxgloves growing in my yard. The seeds are pretty small and I don't have them in an easily accessible area.

The whole plant is toxic. But it is also used in heart meds. As for animals avoiding eating it, it is hard wired into them i.e. instinct. If something has a certain color or smell they wont eat it. Especially if they have eaten it and gotten sick before.

Most of the companion recommendation are for spring plants that bloom roughly about the same time as Hellebore. Are there plants that one can pair with that blooms in summer and fall (in the shade of course).

Thanks everyone for the replies so far.

Paul

I planted a couple of hellebores some 20 years ago, one lenten rose (Orientalis) and one Christmas rose (niger), and they have both colonized well, flinging seeds everywhere if I don't remember to cut the spent flowers.

I've moved them all over the place when I spot the seedlings coming up where I don't want them (in the cracks of the patio, mostly) and so far they don't object at all to being relocated.

The niger is not nearly as prolific as the orientalis, tho there are usually hundreds of seedlings under the old plant.

I find that the orientalis produces lots of variegation in blooms, from pale pink to deep purple. I love the leathery evergreen foliage, and I always cut off the old leaves in the spring and let the new stuff grow. The old plants are nearly 4' across and have hundreds of blooms, so I give them lots of space. They look wondeful with hostas and ferns.

I spent a couple of hours today in fact, digging up bricks in the patio to get the teenage seedlings out of the cracks and replanted them down in the woods gardens. I must have moved 20 of them.

I can't make myself compost any of them, I know how expensive they are to buy! I think I paid over $10 each for the original plants, and that was 20 some years ago!

I have actually bought a few of the newer varieties in the last couple of years. They all grow fairly slowly so don't expect immediate huge plants, but one year you will look at them and go, WOW!

They seem to grow well in partial or filtered shade, average soil with minimal water. I don't find them fussy at all.

There are two ideal times to plant most perennials; spring and Fall.

Of course it depends on the type of plant you are working with, but many perennial plants actually grow over much of what we think of as "winter" when most people think of their gardens as dead. They will produce a second type of leaf that can survive the freeze/thaw cycles - it is often more leathery than the other leaves and takes on a reddish hue in many plants - and many of them are producing those leaves as we speak, even as this year's summer growth is dying back.

Take a walk outside in November after the annuals are dead, and you'll find there's still a lot of green out there, though most of it is confined to the base of the plants right above the soil. Even when the frozen air temperatures make it difficult for perennials to move water to their stems and they die, some leaves at the ground level are basically evergreen.

You'll notice that a lot of spring and summer blooming perennials that re-seed will wait until fall to sprout, or else will sprout in the very early spring when there are still regular nightly frosts, and I bet there are a lot of sprouts in your garden right now, including some from weeds. That's because cooler temperatures help plants conserve moisture while they're young and don't have the root systems to survive summer heat, but these particular varieties can freeze/thaw with no problem.

A lot of plants actually grow quite a bit in what you normally think of as "winter." Here in Colorado - zone five - I am watching oriental poppies and grape hyacinths emerge from dormancy to put out leaves right now. Other perennial plants - irises, day lillies, and penstemon, are producing new rosettes of leaves at the base. I am noticing a lot of columbine seeds are sprouting right now, and huchera and sedum are continuing to grow leaves.

Even the first hard frost that kills all the annuals won't stop some perennials from continuing growth until December.

Then in February, crocuses and other early spring bulbs will be emerging, and some those perennials that grew through December will start wake back up again then and continue building the root systems.

Most sellers are not going to ship plants unless they can be planted now and survive; maybe a few will, but it's not very good for attracting return business.

Atekk, in my zone where Buddleia can be borderline cold-hardy, I would definitely not plant a Buddleia in the fall. It needs an established root system, and significant top growth to survive the winter here. I would still be cautious in zone 6, but they might do okay if you plant them in a sheltered microclimate. To be safe, you could have them shipped in the Spring.

From what I've read, plants' roots will continue to grow until the soil temperature is below 40 degrees. Roots are much less cold hardy than top growth, but this is not a problem because the soil temperature would be warmer than the ambient temperature for most of the winter. This is why most plants in pots need to be mulched heavily, sunk in the ground, or somehow sheltered to survive the winter.

Then you have plants like Daylilies that are so hardy that I dug up a root ball and accidentally left it hanging out by the compost pile all winter, and it survived.

Hi! If anyone is still going to read this...

I just found out that my lavender is actually lavender multifida or Spanish Eyes! Apparently it is quite a hardy thing and can take humidity (probably explains why its still alive) well.

I will probably take the entire pot indoors for the winter from December to February, as its still a young thing.

My question is: Many plants go dormant in winter, which helps them to rest and reboot for spring. If I bring my lavender inside, will it mess up its system cos it cannot hibernate? My house is almost like a greenhouse because I have large glass walls instead of concrete walls, and the indoors plants get a good amount of sunlight.

Any other information and advice pertaining to growing this type of lavender very much appreciated!! The leaves are starting to smell good already!

Thanks very much to anyone still reading this thread.

If they are hardy in the area I would plant them outside and mulch around the plants. Even hardy small plants survive the winter here. Think of all the self sown columbine and other plants that sprout in the fall.

I have grown lavender inside under lights during the winter and planted them outside when spring came. They grew well both inside and out. Didn't need to go dormant.

Sorry, no help on the Spanish lavender which is not hardy in Z4. It is sold and treated as an annual here.

If you want aggressive groundcovers that spread quickly - but don't invade or affect your larger plants - I have a few I like to use, which are common, easy to find and well-known:

Ajuga reptans var. 'Bronze Beauty' - nice dark-leafed groundcover (a mottle of dark purple and olive green leaves) that is very shade-tolerant for the areas closest to the house. Short blue flower spikes in the spring. It will survive droughts but if there's water available it will grow very dense, to make it absolutely impossible for weed seeds to sprout from within it. But it's shallow-rooted so won't compete with your plants, nor will it shade them because it never grows more than 3 inches from the ground. It's easy to spread around by digging small bits that take well even in heat.

Sedum spurium 'Red Carpet' - A very attractive red-leafed sedum that will really stand out in contrast to those varigated irises if planted right next to and among them. It is also very low-growing, drought-tolerant so it will not take water that could be going to your other plants, and this particular variety grows pretty slow.

Sedum spurium 'Tricolor' - similar to 'Red carpet' but grows more quickly, has a green/white leaf that has a very visible pink blush over it when it's exposed to direct sun; it also turns more pink in the winter, and has pink flowers.

Cerastium tomentosum ('Snow In Summer') - spreading silver-leafed ground cover that is also reliably less than 4 inches high, gets absolutely covered in white flowers in the early summer, and would pop against the ajuga and red-leafed sedum. It wouldn't contrast as well against the iris so I wouldn't plant it right there, but because it's the most drought-tolerant, I'd put it right up against the edge of the garden.

It looks like you are very keen on symmetry. That means that gardening with picky plants is not a good idea, since, though it might be easy enough to get them to survive, it's more likely that they'll thrive on one side and not on the other. You can save them for your garden elsewhere.

I would throw in some oriental poppies, for good measure, just behind the irises where they they can be cut down for their summer dormancy.

Then I'd scatter the whole thing with some naturalizing spring bulbs ... daffodils, crocus, species tulips etc.

I'd plant them right inside the groundcovers so that their dying leaves blend in and are eventually covered.

I'd also plant an aggressive (but very short) groundcover right on top of our allium bulbs so that that foliage is overtaken as soon as it dies.

It is a hybrid cross of longispicata x farinacea, bred by BallFloraplant. Propagated vegetatively. Hardy to zone 7

I have may night salvia blooming now.

It is a vigorous re-seeder and can take over the garden, then look really bad after it blooms and flops over. Deadheading it returns it to fresh growth, but again, it will bloom and then look ugly.

I find that it is better in part shade where it is not as vigorous.

May night salvia is extremely easy to grow. You can cut it back to the base or it can die back, and it will re-grow, any number of times. It's drought-tolerant but if for any reason you let it get really dry and die, it will simply die back to the ground level and re-grow. Also, tiny pieces of severed roots will re-grow. As far as I can tell, it basically takes on the growth habits of difficult weeds like bindweed or thistle.

That makes it really easy to propagate, especially since root cuttings can be completely buried and therefore you can take and re-plant them directly into the garden, any time of year. But be aware that it's very hard to get rid of when it gets established somewhere.

hi again

stupid question...

i'm going to roundup my space. after the weeds die can i work them into he soil or do i have to remove them?

Depends if they have gone to seed. If they have gone to seed, you want to remove them and put them in the trash so that you aren't adding all those weed seeds to your planting area. If they don't have seeds (pretty unlikely this late in the season) you can turn them into the soil.

Aster Purple Dome is wonderful this year. In many years, it gets brown and ratty foliage from ground to mid-plant. This year, with ample rainfall, it is quite healthy looking.

I *love* Japanese anemones! I have "Honorine Jobert" and "Pamina".

I'd actually prefer it to not bloom, not because of appearance (which for me was beautiful - bright white and very full) but because of the potential for it to become invasive. I purchased four plants from a garden center last year, and the same season I planted it, it grew to over 3 feet, with profuse blooming in the fall (small flowers but millions of them.)

Unfortunately, I had rather stupidly planted it as a foundation plant for the front of my house. It looked GORGEOUS in between dwarf boxwoods (as foliage, or as a blooming plant), but of course it dies down to nothing, and is then unusually slow to come up in the spring, so I had big empty spots in spring.

I also read more and more about how much it self-sows... it is supposedly not much of a problem in the first couple years, but then becomes a big problem a few years down the line. I mulch the foundation area carefully, but I was worried about it spreading elsewhere. There are so many flowers that it's impossible to remove them before they go to seed.... not a problem if you're planting it in a wild setting or a "wild garden" setting, but a problem for a more formal area.

This spring, when they finally began to come up (June before there was anything significant), I ended up digging them up and replacing them with dwarf azalea with white flowers - it's actually a similar look, but evergreen, which is important for me with harsh NH winters. Unfortunately the flowers come in late spring rather than fall, though. I enjoyed the show last fall.

While I don't THINK I got "volunteer" seedlings from the Eupatorium I had planted, I *did* get seedlings from something else (wild Joe Pye?) which made its way into my yard. Whatever it is is clearly invasive and very difficult to remove, and is ALL over. The leaves are a lighter green, which is why I assume it has nothing to do with the "chocolate" plant I planted. But, the problem with what I assume to be wild Joe Pye also scared me enough to make me not only dig up the "chocolate" but discard it rather than replanting elsewhere.

I get some self-seeding, but nothing invasive.

I always leave garden cleanup for spring. Winter here is about snow, so it is good to leave some sort of form and structure behind. Birds and other animals will eat the seed and cleanup in spring is a breeze after winter has done its work.
Wieslaw, what kind of echinacea do you grow?

To prevent self sowing I cut the dried seed heads and place them in a 5 gal pail full of soil/sand which I place near the bird feeders. The birds get seed to eat and I have fewer seedlings to move or compost the next spring.

I tried leaving the seed heads on plants over the winter but find that we get so much snow that plants don't last long before the stems are broken and/or they are covered. Not an effective winter interest item for me. I don't cut back my red twig dogwood until spring. Those red twigs hold up well and if the deer don't eat them they make a nice winter accent.

Yes, my aster is in full sun. Since I divide mine every year, that particular plant is probably 18 inches tall and maybe 2 feet across.

Kevin

Think I figured it out. This plant only flowers on new growth wood. Not having cut back last years plants to the ground the new growth just added itself to the old which doesn't produce new greenery or flowers.
If I had the blooms are great right now but the old woody growth from last year couldn't support the new since the plant is now top heavy.

Question .... should I have cut it right back to the ground in late fall after the blooms die or wait 'til spring before it starts to grown. I think that's called keeping the plants "under control" (lol). Thanks folks for the help. This my first year with this plant.