“Ask John!”

John loves hearing from his customers and do they love to ask him questions! Each conversation features a question submitted by someone like you.

Have a garden-related question?  
Email us: Stephanie.Christiansons@gmail.com

Listen to “The Garden Show” with John and Mike
Sunday Mornings at 10:30 a.m.
KAPS AM 660 and FM 102.1

October 8, 2020


Q: Hello John,
We purchased two Jasmine plants from you in early spring this year. They are both so beautiful and have grown well over the summer. Question; what should I do over winter to keep them safe from dying? One is potted and sits on our deck and the second one is planted in the ground. Look forward to hearing from you.
Many thanks,
Kim W., Mount Vernon, WA


A: Dear Kim,
Jasmines are one of the most exotically fragrant vines we offer. Winter hardiness depends on the type. I might guess you have Star Jasmine, the most popular one, that flowers all summer.
In the ground, they are reasonably hardy, except in the coldest areas – north in Whatcom County would be more challenging, as would Sedro Woolley and east. They prefer full sun.
In pots, you would need to bring them indoors if temperatures drop below 30 degrees. The roots are not as hardy as the tops. Prune them lightly in March, fertilize in April, and enjoy blooms all summer long.


Happy Gardening!

John Christianson


August 3, 2020


Q: Hello John,
How do I get rid of mildew on my plants, specifically deciduous azaleas?
Many thanks,
Delinda, Mount Vernon, WA


A: Dear Delinda,
Some of the most awesome flower colors come from deciduous azaleas. Fragrant yellow, orange, and red flowers out-compete most other shrubs in May.
Powdery mildew is a common malady in late summer, covering the leaf tips with white, powdery mildew.
If you ignore it, the plant is perfectly healthy, and the leaves will drop off in the Fall; the fresh leaves arrive in Spring. To prevent it from spreading, at the first sign of mildew, spray with Bi-Carb (baking soda) or Safer’s Fungicide (sulfur), both available at the Garden Store. This treatment also works well on Dahlias and Veronica. Rake up all the leaves in the Fall and throw them away being mindful not to compost the mildewed leaves.


Happy Gardening!
John Christianson


July 3, 2020
Q: Hi John, The peach tree I purchased last year has leaves that are curling. Is it an insect or a disease? Thanks. –Dirk, Snohomish, WA


A: Hello Dirk, You are not alone this year with a rather common disease; Peach Leaf Curl. The most disease-resistant variety (and our most popular) is our locally grown ‘Frost’ peach. Even with natural resistance, young trees are subject to leaf curl and will develop resistance with maturity.
Your current diseased leaves will fall off, and fresh, healthy foliage will emerge by mid-summer. Preventative spraying in mid-December, January, and February with copper spray will prevent the problem.
John Christianson


Q: Hi John, I have heard of three different ways to fertilize azaleas and am hoping for clarification. The first is that azaleas need no fertilizer before, during, or after blooming. The second is they need fertilizer just before they bloom, and the third, they need fertilizer after they bloom. We live up the hill from the Nursery where we have a slightly colder microclimate and our azaleas have yet to bloom. What do you suggest, John?

Thank you,
Susan D., Pleasant Ridge, Mount Vernon


A: Dear Susan,
Azaleas (as well as Rhododendrons) are easy to grow and are well adapted to the Pacific Northwest. Because of their shallow roots, keeping them well-watered while getting established in critical. Ample composted organic matter around the plant makes moisture retention much easier.
Applying organic fertilizer is beneficial twice a year. We recommend using E.B. Stone’s Rhododendron, Azalea, and Camellia fertilizer for acid-loving plants, which is sold at the Garden Store. Fertilize in February or early March to enhance growth and improve health. However, the most critical time is late May or June for feeding. All flowers are produced the previous year on new growth. Fertilizer in June ensures great flowers next spring. Prune right after blossoms fade to keep them full and bushy and loaded with buds for next year.
John Christianson


Q: Hello John,
We have just hired a landscape designer to help make sense of our overgrown yard. While making decisions on which plants to take out, which plants to move, and which plants to add, he suggested planting a couple of “bare root” apple and nut trees. We have never heard of “bare root” plants but he suggested that we check out Christianson’s to learn more. What do you suggest?
Sincerely, Karla and John, Mount Vernon, WA


A: Dear Karla and John,
Late winter is a great time to imagine what your garden may become with apple, pears, plums, and peach trees growing at your fingertips for fall harvest. Now through the end of March is our bare root season which describes a “no packaging” feature; bare root trees, plants, and shrubs are not potted up like the rest of our plants. All of our bare root offerings are sold without soil or a pot.
On average, our bare root plants cost 30% less than potted plants, and will adapt quickly in your native soil. They are labeled and heeled (stored) into sawdust-filled raised beds or tables. Simply locate the desired plant, lift and shake off the sawdust, and place it into a plastic bag (located near each bed or table).
Some suggestions that grow well in the Pacific Northwest are the new ‘Cosmic Crisp’, and ‘Honeycrisp’ apples, and heirlooms ‘Gravenstein’, ‘King’, or ‘Yellow Transparent’. For nut trees, consider this year’s new disease and blight resistant filberts. With up to seven varieties, you’re sure to find on you’ll like.
 John Christianson


Q: Hello John,
I’ve a question on the 3 Forest Pansy Redbud trees that my wife brought home from the Nursery. They were burlap wrapped. Their root structure was very minimal. It was more like a very sparse bare root fruit tree packed in a dirt ball. Is that expected? They are in ground now and hopefully will have plenty of opportunity to regrow roots come spring. Thank you, Dan & Moira, La Conner, WA


A: Dear Dan and Moira,
Our balled and burlap trees are usually sensitive to digging, so the burlap assures that the roots are undisturbed. Cercis, Ginkgos, dogwoods and Magnolias are all in that class. It is best to set the trees in the hole, burlap intact, and back fill halfway with soil and then peel only the top of the burlap back. The burlap will biodegrade rather quickly. This also ensures that the top of the root ball is at the same grade as the surrounding soil (not deeper). Not disturbing the roots is key to transplanting success. This is a great time to plant trees.
 John Christianson


Q: Hi John,

Right now I am concerned about green aphids that I have on my rose bush.  I checked it last night when I got home from work and those aphids are everywhere.  I am surprised they are present amidst this cold weather.  Rachael, Seattle, WA


A:   Hello Rachael,

Aphids in the dead of winter?   It is unusual to see these green aphids on your rose bush outdoors, especially with the cold weather Seattle has had.    However, all roses are susceptible to aphids.  

The best remedy to take is to cut off the effected area of new growth and place it in a plastic bag to throw away.  If there are too many branches to sacrifice, try using Safers Soap.  Safers Soap is considered organic and it works ‘on contact’.  You may need to spray more than once.
Hopefully, you will soon have new growth with budding roses by May.
Best, John Christianson  



Q: Hi John, Do you think that early February would be an OK time to plant roses (into the ground)?  Miriam S.

A: This is a timely question, Miriam. February is still a good time to plant roses, although you may want to mulch up to the cane until the end of the month. The greatest problem with planting in early February may be digging a hole if the ground is frozen ground.

John Christianson


Q:  Hi John,  We are choosing a balled & burlap living tree from your Nursery for Christmas this year but I am worried about keeping it alive through the holiday.  How should I care for it?  Thank you and Merry Christmas!   Jane, Sedro-Woolley, WA

A: Hi Jane,
Care for balled & burlap living Christmas trees are similar in maintenance to cut trees once inside the house.  With a living tree, however, it should not be moved directly indoors. Instead, it’s best to first transition it to a porch or a garage allowing it to acclimate to warmer temperatures.  Plan to bring it indoors for a maximum of two weeks (around December 11) and water it daily!!!  They take a lot of water; think how much a cut tree absorbs – and they don’t even have roots!  Right after Christmas move it outside.  You don’t want the tree to get comfortable and begin growing roots prematurely.  If temperatures are freezing, transition it back to your porch or garage for a few days so it’s not put out directly into the cold.

December and January are still good months to plant trees, including your balled & burlap live Christmas tree.  Plant your tree, then loosen the top of the burlap bag and remove the synthetic twine around it.  Roots grow quickly this time of the year which will support growth in the spring. Remember to water throughout the summer of the first year of growth.

Wishing you a Happy Holiday!


Q: Do you have garlic bulbs in yet?  If so, what varieties do you have and which are the best for cooking?  Betty Lou, Mount Vernon, WA

A: Hello Betty Lou, not only is fall a good time to get your soil ready to plant garlic, spring is, too.

We carry true garlic (species: Allium sativum) which has two subspecies, both hardneck (Allium sativum ophioscorodon) and softneck (Allium sativum var. sativum).

The hardneck varieties are characterized by woody central stocks, a long flower stalk (scape) and fewer, larger cloves. Hardneck garlic (rocambole, porcelain and purple stripe) tends to grow best in areas with very cold winters so they can be dormant then flower in the spring.  Use for roasts with gamier meats, like duck or venison as well as vinaigrette.  Try these: rocambole garlic ‘German Red’ and ‘Spanish Roja’.

Softneck varieties produce more cloves and tend to have a grassy, plant-like taste without the bite hardnecks have.  If you want to eat or use garlic raw or lightly cooked, you’ll probably head for a softneck variety. Try these: artichoke garlic ‘Early Italian Purple’ and silverskin garlic ‘Italian Late’.



Q: I called the Nursery on Sunday to be reminded of the when and where’s of John’s garden show and was told we can now stream them online (and offline if we set up an account) on SoundCloud?  Is that true?  If so, how do I stream them?
-Ellen, Snohomish

A: Hi Ellen, Yes, we are live on SoundCloud, which is a free-listening platform.  I had to ask our PR person about this and she suggested to go to www.soundcloud.com in your web browser.  Once you’re on your home page for SoundCloud, use the search field and type in Christianson’s Nursery.  Once the list of tracks populate, simply pick a date you are interested in and click the orange circle to play it.  Make sure your sound is up high enough to hear the radio show!


Q:  Hi John,
I purchased the ‘Gentle Hermione’ David Austen Rose about a year ago. She bloomed beautifully early this season, having 44 blossoms before a rest. Presently, she is blooming again with fewer blossoms. The bush has also produced a few very long canes. Some of these have buds, but three canes show no signs of buds yet & two of those are extra thorny.
My question: I am wondering if I should cut back the non-blooming canes to a similar height as those that are or have produced blossoms. I hope the photos are helpful.  Louise, Orcas Island, WA

A:  Hello Louise,
Your roses look super healthy.  Some David Austin roses are shy to bloom in Autumn. This rose is not grafted but is growing on its own roots , even though some canes are taller and arching they are not grafted under stock.

You have three good options:

1.) Cut back the tall canes by a third to maintain the shape and balance of the plant.

2.) Peg it!  Depending on the size of your garden, you could peg the long canes to the ground on both sides of the rose bush to create beautiful hedging affect.  Next year you would have a flowering plant three times as wide your present ‘Gentle Hermione’.

3.) Do nothing-the tall canes will still flower next year.

Wishing you all the best,

John Christianson


Q:  Hello!
I have an emerald green arborvitae hedge along the back and side edges of my property.  I have noticed within the past couple weeks that some of the leaves on them are turning brown and some are even black, but those are more on the inside of the trees.  Elsewhere on the trees, there appears to be healthy green new growth.

I had some bark mulch laid underneath last summer, so there is probably 3 to 4 inches of mulch around the trunks.  I applied some 16-16-16 granulated fertilizer to my flower beds and the hedge about a month ago, thinking that it would help everything grow.  I don’t see any spider mites on the trees, though on a rare occasion I will see a moth fly out of the trees.  They don’t seem to be infested with moths though.

Any advice you can provide would be much appreciated! Brian Gregory, Ferndale

A:  Hello Brian,
It sounds like you’re back on the right track for watering your arborvitae hedge. The browning leaves were most likely caused by the missed watering when the irrigation wasn’t set up right. Other things that could affect it are (this year’s) drought stress or (last year’s) winter damage.

The browning or black on the insides is a common characteristic of arborvitae and that’s just because the insides don’t get any sun. This doesn’t hurt the trees at all and is more of an aesthetics issue. You can try to cut out some of the brown on the outsides, but I really think if you stick to the regimen you have for them now, you’ll find they’ll start greening up and looking pretty again.

You were just fine fertilizing it when you did. We always recommend a straight across the board, slow release fertilizer and it sounds like that’s what you put on it, so no worries there.

Spider mites more are more of an issue on the eastern side of the mountains, but not here. There really are very few, if any, issues that just up and kill arborvitae hedges. That’s why everyone uses them as natural privacy fences.   It’s also normal to see the occasional moth fly out, but there’s not a common issue with moths infesting or destroying arborvitaes.

You’re doing everything recommended to get them to perk back up so now be patient.  Keep up the good work!

John Christianson


Q: Hi John,
Recently I had a red puffy rash on my face after pulling weeds. My doctor said a man was hospitalized for handling the same plant I did. It looks like a rhododendron leaf, bright green, shiny, has a long tap root and is difficult to pull out. Do you know the name of this noxious plant? -Marci

A: Dear Marci,
I honestly can’t think of any shrubs causing dermal toxicity. By your description, it sounds like Daphne Laureola: similar leaves and taproot. In absence of seeing the flower or bringing in a leaf it is hard to guess what it is.

I would consider bringing a sample to WSU Research Extension near the airport. Maybe they can identify it for you.

John Christianson


Q: Hi John,
Snails..  they just seem to love my Hosta’s, well not just the Hosta’s.   Please tell me how to keep snails at bay or even get rid of them.  Currently I have a band of copper around them and have been using Sluggo.  The issue I have with the Sluggo is that a crow keeps eating it.

I’d sure appreciate your solutions. Thank you in advance.  Trish A. Mount Vernon, WA

A: Hello Trish,
What you are doing is effective.  It is pretty hard to beat that combination.  Aside from putting on gloves and hand picking (probably) hundreds of mollusks would be to try Cory’s (molluscicide) with Sodium Ferric EDTA.  If that still doesn’t work, the final (off the shelf) step would be to use Deadline (mini pellets) containing Metaldehyde.
Happy trails,  John



Q: Hi John,
I planted this tree last summer. It was leafed out and appeared healthy last year. It grew buds earlier this spring but now the buds look like they are getting hard and dying?  Just noticed recently that the trunk color turned brown about one foot from the ground?

Any thoughts on what is going on? Thanks, Steve D., Sedro Woolley, WA


A: Dear Steve,
It is a Striped Maple tree. The young bark will always be striped and then it fades as it matures. The discolor on the trunk may be due to transition from young to mature bark.  I am questioning if the tree has a canker (fungal disease caused by stress). If you see spores on it that is a clue.  I suggest that you prune back the branch that looks affected to control potential disease.  There are no sprays or chemicals to control the fungi that cause the disease.

Best, John


Q:Hi John,
I have a shady spot leading up to my front door and need advice on what to plant there.  The soil is wet and soggy.  What do you suggest?  Love your nursery!   Nora, La Conner, WA

A:  Hello Nora,
A couple of shade and wet plants that would do well in your spot are hostas and sarcococca.  Hostas are most attractive from spring to fall, but no winter interest.  Sarcococca can take wet but not puddling.  They are a broad leaf evergreen with great winter-blooming fragrant flowers. 
John Christianson


Q: Hi John,
What’s going on with my shrub? It was healthy last year and slowly over the winter this flagging to occur.  Should we tear it out or can you suggest a method to revive it?  Tiffany, Bow, WA

A: Hello Tiffany,
Your Boulevard Cypress could be flagging which occurs mostly to older needles and usually affects just the interior. Wait for new growth, then cut back the brown needles until it reaches new, green growth. If the brown needles go to the tip, you may have to remove the whole branch!
Regards, John



Q: Hi John,
I bought this rose Owl Eye a climbing rose several years ago before I knew that you shouldn’t bury the graft junction. The majority of these canes look very straight like suckers and I wonder if you can tell by the photo if the canes are rootstock canes?
Thank you. Jeanne M., Camano Island, WA


A: Hello Jeanne,
The canes look like they are the original Owl Eye. The absence of the thorniness of typical rootstock is a clue.  Be careful to not over prune your climber, the flowers only emerge from the previous years wood. Now is a good time to fertilize to ensure more blossoms.
Sincerely,  John Christianson


Q:  Hi John,
I’m looking for an evergreen plant, bush or vine that can be used to create privacy on a back porch.  It needs to be in a pot and reach at least 5 feet tall.  Any ideas?  Jennifer D., Anacortes, WA

A:   Hi Jennifer,
Here are some ideas for your pots:  Espaliered Euonymus, Camellia, Laurus nobilis (Bay), Evergreen clematis: Armandii or Avalanche.  These will stay a nice size for potting and create the privacy you want.  All of these are available at the Nursery.
Best,  JC


Q:  Do you offer a beginner gardening class this summer? Customer from the Garden Store

A: Yes!  We have a Saturday class on June 3 at 1:00 p.m. with Cyndi Stuart from The Roost at Roddy Creek.  Cyndi’s high energy will rub off on you as she teaches how to start veggies from seed or plant starts and how to get your ground ready for a successful first season of growing your own harvest.  See our class calendar at: www.ChristiansonsNursery.com.

Regards,  John Christianson