Milkweed

Like many gardeners, I grow milkweed because I think it is pretty but mainly for the butterflies. Butterflies of many kinds enjoy sipping from its flowers, but butterflies like the Monarch and the Queen are completely dependent upon it for the nurturing of their larvae. 

As we know, the Monarch in particular has been declining in recent years and one of the reasons has been the destruction of milkweed plants by industrial and agricultural development along its migration route across the continent.

Throughout the year, the Monarchs flit through my garden and many of them lay their eggs on the milkweed plants there.

And soon I find their caterpillars happily munching their way through the leaves of the plants. A heavy crop of caterpillars can completely strip the leaves from a plant in a few days. Through our long growing season, an individual plant may regrow its leaves several times.

Nearing the end of the season, the plants develop their feathery seeds which will be spread by the wind if the gardener doesn't remove them. The result can be "volunteer" milkweed sprouts in unlikely, unexpected places around the garden.

Also, as the season advances, the plants are host to many different insects like the milkweed bug in the above picture. As the plant declines, they signal their vulnerability to the insect world and become prey to more sinister leaf chompers and suckers.

The most destructive of these, from my point of view, are the aphids. A crop of these can really uglify a plant in short order.

I would prune off the affected limbs along with their squatters except for one thing: Where there are aphids, there are ladybugs on the job.
  

Ladybugs love aphids! Over a few days, they will completely scour a plant of them. Then will be the time to cut the plant back and let it regenerate.

  
Even more voracious devourers of the aphids than the adult ladybugs are their larvae, like this little guy. It takes a lot of aphids to transform this into an adult ladybug and that's good news for the gardener.

Also aiding in the fight against bad bugs are spiders like this tiny jumping spider.  

By this time of year, the milkweed plants that were so pristine and pretty in the spring have become an eyesore in the garden. But they are still providing important habitat and food for many insects, arthropods, amphibians, and reptiles. Gardeners who understand this can easily tolerate the ugliness for a while. When the aphids are gone, the plants can be cut back and, at least here in zone 9a, they will regenerate and probably be in flower again before the end of the year. 

Ready to sustain and nurture more generations of Monarchs and Queens.

Unofficial milkweed field trial

Over the past year, there has been a good bit of publicity and discussion in gardening circles about the efficacy of planting tropical milkweed (Asclepias curassavica) in our butterfly gardens as an aid to Monarch and other milkweed butterflies. There has been research that has indicated that this non-native plant might actually be harming these butterflies and urging gardeners to plant native milkweed instead. 

For the past several years, the only milkweed that I had found available in local nurseries was the tropical kind, and so I had planted it in my garden where it has thrived. It lives through the winter here, although it generally dies back to the roots, and I usually cut it back several times during the year. Cutting it back supposedly reduces the toxins which may cause problems for butterflies, and, if it isn't cut back, it gets quite spindly and gangly and not very attractive. But the butterflies seemed to like it. Maybe because there wasn't an alternative for them.

So, I decided to give them an alternative.

After reviewing my options, I decided to order some seeds from Botanical Interests during this past winter. I planted the seeds of butterflyweed (Asclepias tuberosa) and swamp milkweed (Asclepias incarnata) and started the plants under my grow-lights. 

Most of the seeds germinated and the plants thrived, so by late spring, I had two trays of native milkweed to plant in my garden. I put the plants outside for hardening off and planned how I would monitor both these plants and the tropical milkweed, which was already up and blooming, to try to determine if the butterflies actually showed a preference.

It didn't take long to get the first data from my unofficial milkweed field trial. By the time I went to put my native plants into my garden beds, I found that, in spite of the fact that the plants were still small and had no blooms, several of them already had tiny Monarch caterpillars on them! Meanwhile, all the tropical plants were bushy and healthy and blooming and notably caterpillar-free. The Monarchs had spoken loudly and clearly: They preferred the native plants.

And that has continued to be case. Here is a look at some of my plants today.

This is some of my native milkweed. It all looks like this today. Nothing but stems because the leaves have been devoured by several caterpillars. Actually, it has already started coming back because a few days ago it had no leaves at all. If only the butterflies will leave it alone for a while, it will eventually grow back all the way. Maybe it will even get a chance to bloom.

And here is some of the tropical milkweed, healthy and blooming. These last few days, I have noted a few Monarch butterflies visiting these plants. Once again, until the native plants grow back, they have little alternative if they have eggs to lay. 

There are some Monarch eggs scattered about on this plant. I expect to see caterpillars soon.

 

My thoroughly unscientific, anecdotal conclusion is this: Monarch butterflies will lay their eggs on native milkweed plants whenever they have that choice. If they have no choice, they'll settle for the non-native plants.

My advice to gardeners based on my findings is to locate native plants or get the seeds and start your own and plant them in your garden. Your butterflies will thank you. 

Backyard Nature Wednesday: Milkweed + Aphids = Ladybugs

Milkweed is well known as the host plant for Monarch and Queen butterflies. It is the only plant that their caterpillars can live on and so it is absolutely essential for their survival.

But milkweed not only attracts Monarch and Queen butterflies. It is also a magnet for a somewhat less charismatic insect. Aphids.

Here is one of the milkweed plants currently in my garden. All those little yellow bits are aphids, sucking insects which, in a heavy infestation, can devastate a plant.

The only thing good that can be said about aphids is that they provide tasty snacks for several predators. Including ladybugs.

Here is a member of my ladybug army making quick work of a few aphids on this plant.

Ladybugs, like the milkweed itself, come in different colors and color patterns. Here is a different type that is cleaning up this plant.

And here is yet another type that has its work cut out for it on this heavily infested plant.

Fortunately, it has some allies to help.

Though the ladybug army is badly outnumbered, there are implacable in their pursuit of aphids. Given a few days, they can gobble up amazing quantities of their favorite squishy yellow entree.

The milkweed, damaged by both the aphids and the caterpillars, will recover and in time will grow new leaves and become a nice bushy plant once again. In the meantime, they can look pretty nasty and they certainly don't add much beauty to the garden, but I grow them not so much for their beauty as for their usefulness to the butterflies that I want to see prosper. The fact that they also set the dinner table for the wonderful little ladybug beetles is simply lagniappe - one of the many pleasures of the pesticide-free garden.  

Wordless Wednesday: The muncher

Wordless Wednesday: A Queen on her milkweed throne