Jeremy Siegel: This is GBH’s Morning Edition. A cloud of pollen. That sounds like a figure of speech. But yesterday it was a reality as a yellowish, powdery haze floated above the greater Boston area.

Paris Alston: Here to talk more about it and to answer your questions about the weather and gardening is GBH meteorologist and plant expert Dave Epstein. Hey there, Dave.

Dave Epstein: Good morning to both of you. Good to be here.

Siegel: A pollen cloud. How does that happen?

Epstein: Yeah. So the pines are releasing their pollen this time of the year. And so when you get a little breeze or any sort of movement of the air through the trees, it kind of comes out and it goes all over everything. And you can see that the pines are all releasing their pollen roughly at the same time, because it’s basically the same varieties of pines around here. So that’s why we’re getting the pollen clouds all over the place and a lot of that yellowy-green stuff on your car and on the deck, and it’s everywhere.

Alston: Now, if anyone wants to see a picture of this, the photographer Ed Hughes shared a picture of it on Twitter-slash-X yesterday, saying, this is making the lives of allergy sufferers miserable. But, Dave, last week you mentioned that most of us aren’t allergic to pine pollen and that there are, in fact, different kinds of pollen in the atmosphere that can trigger those allergies. So are both types, are all different types in this cloud, and what determines when the pollen is going to fall to your car versus staying in the atmosphere and irritating you?

Epstein: Yeah. So the difference is, is that the pine pollen is large, so it’s roughly 100 microns large. As you get down to the grass pollen, that’s about 20. And some of the other pollens are down around 10. So it just depends on the type of pollen. And we don’t see the pollen. The smaller ones are able to get into your nasal passages a little easier and cause those allergies. So no one’s — not no one. It’s very rare for somebody to be allergic to pine pollen. So the X post saying that this is why people have allergies, it’s not true. It may bother you, you know, you may get some of that pollen, like getting dust in your eye. You may not be allergic to dust, but if you get something in your eye, it kind of makes your eye itch or water a little bit. But it’s not an allergy per se.

Siegel: For people who are suffering from allergies right now, when will we begin to see relief?

Epstein: Well, it depends on what you’re allergic to. So if you’re suffering from allergies right now, it might be some of the tree pollen. It could be the grass pollen. So if you have a grass pollen allergy those will be waning here as we get into later this month and certainly July. And then we get the ragweed late July and August. And that’s sort of the the more autumn pollens that come out later on in the season. And then everything kind of winds down once we get our first frost.

Alston: I love that Jeremy said we, because I am certainly feeling it too there. So we got a few listener questions for you here, Dave. Susan is asking, well, they say, I live in a condo, and I would really like more outdoor privacy. And I’m thinking of growing bamboo and really large planters. Thoughts on bamboos as the hedge solution.

Epstein: Yeah, you can absolutely do it. One of the things that you want to do is ensure that, if you put them in containers, I have actually done it for folks, before in this exact same situation, that you get a variety that is a clumping bamboo and also check the zone hardiness of it, because the containers are going to be above ground, they’re actually going to be exposed to more freeze-thawing. And you want to have them really hearty in a container, but I’ve got some bamboos in containers as well. They do make it through the winter.

Siegel: We have another question from Mark in Framingham who is hoping to find a specific plant. We don’t have a picture of it, so hopefully you can help Mark out or give him some suggestions. Mark asks: what is the lilac-like woody stemmed floral plant about to bloom now with small white flowers and yellow stamens? And can they do well in shaded area? So do you know what he’s talking about? And if not, do you have a recommendation for something that’s pretty and can do well in shaded areas?

Epstein: Yeah, that’s at tough one, sort of based on that. There are — that’s a tough question right off the bat, right off the top of my head to think about.

Alston: Mark, you have to send us a picture if you can.

Epstein: Well there’s some native there’s a native viburnum that’s out there in the woods right now that’s got some white, little white puffy flowers. It almost looks like a hydrangea. And that could be, you know, you find some of those viburnum will do pretty well in sort of part dappled shade kind of environment.

Alston: All right, well, that is meteorologist Dave Epstein. And a reminder that if you ever have a plant or weather related question for Dave, you can always text that to us at (617) 300-2008. Dave, thank you so very much.

Siegel: You’re listening to GBH news.

Meteorologist Dave Epstein is our go-to person for pressing weather questions on everything from winter blizzards to summer droughts. He’s also a horticulturist, meaning he’s an expert in anything that grows leaves and flowers. GBH’s Morning Edition asked our audience for weather and gardening questions, and Epstein graciously answered them on the air.

Have a gardening or weather question for meteorologist Dave Epstein? Tweet him  @GrowingWisdom, email us at  thewakeup@wgbh.org, or text 617-300-2008.

I live in a condo and I would really like more outdoor privacy and am thinking of growing bamboo in really large planters. I assumed this “clumping” bamboo I read about actually is different from the kind that takes over the whole yard, even in planters. I’m hearing it might not be the solution I thought it was. Thoughts on bamboos as the hedge solution? Thanks. —Susan

There are indeed different varieties of bamboo: Clumping and running. Running bamboo is the kind that can indeed take over, but clumping bamboo should not.

“Get a variety that is a clumping bamboo and also check the zone hardiness of it,” Epstein said. “Because the containers are going to be above ground, they’re actually going to be exposed to more freeze-thawing. And you want to have them really hearty in a container.”

Epstein said he’s put some clumping bamboo in containers and, with the right hardiness levels, they last for years without taking over the yard.

“They do make it through the winter,” he said.

What’s a pollen cloud? How does it occur?

It’s pine pollen season, which means pine trees are releasing ubiquitous, yellowy-green pollen that ends up blanketing what feels like every inch of the outdoors.

“When you get a little breeze or any sort of movement of the air through the trees, it kind of comes out and it goes all over everything,” Epstein said. “You can see that the pines are all releasing their pollen roughly at the same time, because it’s basically the same varieties of pines around here. So that’s why we’re getting the pollen clouds all over the place and a lot of that yellowy-green stuff on your car, and on the deck, and it’s everywhere.”

It’s a noticeable type of pollen, but not an allergy concern for most people, even those who experience other kinds of pollen allergies, Epstein said.

“Pine pollen is large, so it’s roughly 100 microns large,” he said. “As you get down to the grass pollen, that’s about 20. And some of the other pollens are down around 10.”

Smaller types of pollen may be more likely to cause the body to produce an allergic reaction. Pine pollen usually doesn’t set off the same processes, but people can notice it bothering them.

“You may get some of that pollen, like getting dust in your eye,” Epstein said. “You may not be allergic to dust, but if you get something in your eye, it kind of makes your eye itch or water a little bit. But it’s not an allergy per se.”

There are other kinds of trees blooming at the moment that may cause those allergy symptoms, he said.

“If you’re suffering from allergies right now, it might be some of the tree pollen. It could be the grass pollen,” he said. “If you have a grass pollen allergy those will be waning here as we get into later this month, and certainly into July. And then we get the ragweed late July and August. And that’s sort of the more autumn pollens that come out later on in the season. And then everything kind of winds down once we get our first frost.”