North Shore Gardener September 2008

Photo: B. Jones

Sept 3 : Mulch on Perennials, Hibiscus Seeds, European Ginger, Fertilizers, Neighbor's Bittersweet Strangling Wisteria

Mulch on perennials
Q: I read somewhere that placing mulch around perennial plants (such as Shasta Daisies and Echinacea, in this case) can inhibit their ability to spread. Is there any truth to this and if so, is there a certain time of year that I could move the mulch away from the base of the plants to allow new shoots to grow?
Thanks for your help.
L.L., Beverly MA

A: Shoots will grow up through a light covering of mulch - what the mulch will prevent is seedlings from re-populating the whole garden!! (But maybe you might want the plant to re-seed... then mulch more heavily after a hard frost to protect plants...)
In the spring, gradually remove mulches as the weather gets warmer - and the plants don't need protection from cold....
In either case, don't pile mulch up too close to the base of the plants - it could cause rot and mildew to form and flourish, and make a cozy, damp home for some unwanted pests, both four-legged and six..

Hibiscus seeds
Q: last year I took the seeds from my perennial hibiscus and planted them this year in a pot. they are about 2 inches tall now. My question is when and if I should plant them in the fall and how. Any suggestions? Your input would be appreciated.
Thx, Denise

A: - And congratulations on your newly grown perennial hibiscus! They are lovely - and I'm sure your neighbors will be very jealous next summer!

-Growers ship the plants in both spring and fall, so the choice is yours - there should be plenty of time for the small plants to get started this late summer/fall, but do it now! - plant on watching them carefully this fall and give them plenty of extra protection this year with mulch - watch out for snow piling on top of the small plants. But they won't be small forever - when planting, allow 3 feet between plants!

-Be prepared! Perennial hibiscus dies down to the ground every winter and is slow to show new growth - don't mistake it for a dead plant next spring - it may take until June to show regrowth. Prune gently in early spring before the new growth appears.

European ginger
Q: I have had a European Ginger plant for many years at one end of my herb garden. For the last two years the plant has started the season will beautiful, glossy leaves but develops some type of rot in the center of the plant by summer. The leaves and stems turn an ugly brown and I trim them off. The newer outside edges of the plant still look healthy. What can I do to cure this problem? My mother gave me this plant several years ago, and I would like to keep it if possible.
I enjoy reading your column, and I look forward to hearing from you.
G. B.,Newton, NH

A: If the plants are in your herb garden, they are most likely getting far too much sun! European Ginger thrives in moist shade, in rich soil. Try transplanting your ginger - it should spread fairly rapidly and make a beautiful ground cover for you - dig in plenty of compost as you plant. It's a beautiful plant with the shiny, dark green leaves!

Fertilizers
Q: I can never remember what fertilizer to use for what – there are so many different kinds, I’m confused. How can I remember?

A: You ‘re in luck! All fertilizers are labeled the same way with the same symbols .. Start on the front of the package: there are three abbreviations or symbols:
N is for nitrogen
P is for phosphorus
K is for potassium
These are the major ingrediants in your fertilizer. But what are they for?
Here’s an easy way to remember: - Think UP, DOWN, and ALL- AROUND !
N is for nitrogen - (think UP!) makes plants above ground grow UP and become greener. You will often see fertilizers with a high first number used in early spring lawn green-up fertilizers. This would not be a good fertilizer for blooming plants because the plant would be encouraged to make lots of foliage, not flowers – but it would be great for your green houseplants, as well as non-blooming ground covers, like ivy.

P is for phosphorus -(think DOWN!) it’s always the second number. Below ground, phosphorus stimulates root growth. It also promotes bloom and fruit growth, and seedling development.

K is for for potassium –(think ALL AROUND) Potassium promotes strong cell walls, health, tolerance to disease and drought and adverse conditions – it’s for general plant health. It is often found in winter fertilizers, particularly for lawns.
Now you have an easy way to remember when you’re standing in the fertilizer department with row upon row of fertilizer: - think UP, DOWN, and ALL- AROUND !

In addition, you can tell the percentage of N and P and K are in every package: There are three numbers, in the same order on every package:
A 3-12-12 ratio, which means nitrogen, is 3 percent of the nutrients, the phosphorus and potassium are both 12 percent.—this is formula is often seen on fall fertilizers.
Why don’t they add up to 100%? Because of “inert” ingrediants – tiny trace elements necessary is tiny amounts for plant health – but inert ingrediants also fill the bag up! Don’t pay for inert ingrediants – sand, etc.
Now you know! Whenever you go to buy fertilizers, you can think UP, DOWN. And ALL AROUND! And you’ll buy the right formula your plants need.

Neighbors bittersweet strangling wisteria
Hello Barbara, I'm hoping that you can help me with a frustrating problem. Bittersweet has traveled under the ground from my neighbors yard and grown up and intermingled with my wisteria arbor. I don't know how to kill it without hurting the wisteria and it is getting more and more invasive...HELP!
Thank you for any suggestions,
A.F.

A: Are the bittersweet vines, which have traveled underground from the neighbors, must be visible as they emerge and strangle the wisteria........
I would cut them at the ground level - and apply Roundup to the cut ends of the stems. The vines on your side of the arbor will die and can be carefully removed, piece by piece, from the wisteria - they will be very visible as they curl up and die!
If you are still speaking to the neighbor, you might suggest that you or he consider digging a trench at the property line and removing bittersweet roots - or simply root-pruning the bittersweet with a sharp spade!
I don't know how far away the wisteria is from the offending bittersweet, so I suggest that you do this carefully so as not to injure the wisteria!

Please write me again if this is not clear - and please let me know what happens!
BB

This week’s dirt…………………………………………………………
September – “When summer gathers up her robes of glory, and, like a dream of beauty, glides away."
- Sarah Helen Power Whitman

Dirty days hath September…
Dirty days hath September…
April, June and November.
From January up to May
The rain it raineth every day.
February hath twenty eight alone,
And all the rest have thirty-one.
If any of them had two and thirty
They'd be just as wet and dirty.

Sept 10 : Dahlia Tubers, Dogwood not Blooming, Lawn/Wild Flowers, Wild Strawberries

Dahlia tubers
Q: I have a question on dahlias. I take my bulbs up every fall and store them in a dry cool place with mulch. I replant them in the spring. This year not one of them grew. I dug a few of them up and they just looked dormant. One was soft and apparently rotting. Is there anything I can do? I thought maybe the excess rain caused the problem?
Thanks, S.

A: With the information given, I think you may be right - does your planting area have proper drainage? Has anything changed: A gutter or downspout leaking, another area draining into the area? You do not mention any insect damage.
I assume you carefully checked the tubers for rot before planting - but could some of them have been rotting in the center - and have gone unnoticed? Did you trim, cut, or divide any of the rotting tubers? If you didn't treat them with a fungicide after cutting, the open, cut ends would have encouraged mold....
Take great care with the remaining tubers this fall as you put them into storage - remember your storage area should be kept BELOW 50 degree temperatures to avoid rot - and tubers must be checked several times during the winter and damaged tubers removed.
Dipping tubers in a solution of 1 cup bleach to 3 gallons of water for a short time - (not overnight! )- will deter mold and rot – allow tubers to dry thoroughly before packing away.....
Next year, double-check the planting bed to be sure it has adequate drainage – add- well composted material with a bit of sand to improve it, if necessary.
And hope for a little less rain next summer!!

Dogwood not blooming
Q: I have a question; I have two dogwood trees which I had planted when I redesigned my back yard five years ago. The white a Cuza blooms every year, looks spectacular, the second is pink, and unlike the white one it has never bloomed. This is most disheartening because I love the pink colored dogwood and specifically chose that color. Do you have any suggestions as to why the pink dogwood does not bloom? They are both in the same spot far enough apart get the same sun exposure. The white has great foliage every year, but alas, never treats me to flowers...

A: (I think you mean Kousa or Cousa dogwood, don't you???) -
Dogwoods, pinks in particular, take time - both to develop age, and to settle-in after being transplanted: the pink tree may have been much younger than you thought when you bought it - not flowering age. And it might still be re-adjusting.......there is also the chance that the tree is suffering from too much nitrogen, perhaps from the run-off from common spring lawn fertilizers.

There are several things that also disturb dogwood bloom:
-Too much sun...dogwoods grow in the under the canopy of the forest and are burned by a full day of hot sun…
- Not enough water! -The springs of '06 and 07 were dry - and the tree could still be stressed. We have certainly made up for past lack of rain this summer - but spring '08 wasn't very wet either and winter was very dry....
- Poor drainage... and drainage can change with the addition of other planting or construction in the area which could change drainage…....
- Yucky dirt!!! - Did you amend the soil properly when the trees were planted?
- And of course, lousy, cold spring weather, which can freeze and damage flower buds.
Hope this helps for next spring! It certainly is worth waiting for - there is certainly nothing prettier than a pink dogwood!

Lawn/wild flowers
Q: After this season, my lawn is really a mess – I want to plant a new lawn but I hate to think of all the care and cost. I’m really sick of the time and money I spend on my lawn every year – next year it’s going to be different, I’ve read about turning my lawn into a wildflower meadow and I figure this could be a lot cheaper – ??

A: The initial cost for prepping an old lawn for a wildflower lawn is about the same as for a newly seeded lawn……even an area for a sod lawn has to be properly prepped.
Grass seed or wildflower seeds aren’t just thrown into the area. The area has to be prepped by a thorough removal of the old turf, or what remains of it – weeds must all be removed by hand or by use of a chemical weed killer. Then the area is leveled and carefully seeded after an appropriate waiting period if you use a chemical. Sometimes additional fertilizers and soil amendments are needed….a soil would be recommended.
- all necessary for both a new lawn or a wildflower meadow.

A good, brand name grass seed will cost you about $8.50 for enough to plant 100 sq. feet – (As an example, 250 sq ft is the area of two parking spaces or 250 sq. ft.!)

A good wildflower mix, formulated for your particular area, will cost about $9.00 for 1 oz, which will plant about 125 sq feet of meadow.

So the seed or soil preparation are not the only questions when it comes to cost-saving – it’s mostly in the after-care:
Some of the many advantage and joys of a wildflower meadow:
Once planted and established, you’ll have to mow only about once or twice a season, once in the fall, when your mowing will help to distribute the current season’s seeds. Remember, please, that a meadow planting will take several years to develop – a newly sodded lawn is there instantly - grass/turf lawn is there in a season.

You’ll save on water – a meadow doesn’t require much if any – a newly seeded or sodded lawn will require daily watering to begin with…

You’ll save on high-priced gas for the mowers and you’ll save your time - and most importantly, you won’t be polluting the air with fumes or noise. According to the EPA, a typical gas-powered lawn mower emits as much pollution in 1 hour as 11 cars.

You'll cut down on noise pollution: Gas mowers produce about 90 decibels of eardrum-rattling sound. Prolonged exposure to noise above 85 decibels damages the cells in the inner ear; chronic exposure is linked to increased anxiety levels, elevated blood pressure, and disrupted sleep. Of course, if you choose to keep your lawn, you could trade your gas mower for a lightweight, push-operated reel model (about $200.) - and burn calories, not carbon.

And you’ll attract lots of new wildlife, from butterflies to birds – don’t worry! There’ll be enough to feed the whole flock.

The disadvantages? A meadow isn’t a playing field for the kids – it’s a beautiful method of conservation….
A meadow of flowers is far “greener” than a traditional lawn! And what could be more beautiful than a field of flowers?

“Wild” strawberries
Q: I've a Q for you. Have my strawberry plants lost their minds? In early May 2007 I bought two dozen plants from a vendor at Todd Farm. Planted them immediately, and expected nothing from them the first year cuz that's to be expected, BUT, two months later I was picking berries! Not a lot, but I couldn't believe I was getting any! Now this June rolls around and ... nothing. The plants stayed little and just sat there. Then, at the end of July, they're blooming and I'm picking strawberries. What up for that? Are there new, later blooming plants and I've got some ?
Thanks for any info. E.

A: Yes, there are early, mid-season and late varieties – and you have no idea which, since they probably weren't labeled at the local farm.
Keep planting the runners as strawberry plants each have a fairly short life, just a few years.
Enjoy the very healthy berries - they have more Vitamin C, pound for pound, than citrus fruit - and a low calorie count, too!

This week’s dirt…………………………………………………………
With the information that the stormy aftermath of hurricanes may be in the area for the next few weeks, we’d like to give you some suggestions: Have a plan:
Take container plants indoors into a porch or garage. If they are too large to be lifted or dragged indoors, like small trees, or large ceramic pots, tip them over and secure them with bricks or stones to prevent rolling in the wind. –Better have them already on the ground than suddenly slammed over by wind guest!
Secure or move indoors any loose items: tables and chairs, lightweight birdbaths, garden tools that might become airborne and cause damage….
Pick some flowers and pick ripe produce, particularly fragile veggies like tomatoes and eggplant and fruits like apples and grapes and pears…. You might as well enjoy them!
And when the storm has passed, put everything back and wait for the next time! Hurricane season will be over November 1.

Sept 17 : Tomatoes being attacked, Mums for multiple uses, Hibiscus care,Giant allium seeds and “garaging” perennials, Iris

Tomatoes being attacked
Q: I think my tomatoes are being eaten by squirrels. They don't eat the whole fruit, but take lots of little bites. I have put nylon net all the way around the plants in case it was some other varmint, but it doesn’t/t help.
Is there anything I can do?
Bill

A: Certainly does sounds like squirrels! If it is, the net won't help a bit - they'll climb right over!
A product called "ShakeAway for Small Critters" would probably work well - buy it at garden centers and just sprinkle the granules around.

Mums for multiple uses
Q: I want to buy some mums to use as table decorations for an anniversary party in October and to place on my front steps. Can I plant them in the garden after I’m through with them?

A: If you are buying mums from a florist, they may not be hardy – ask! If the mums are pot grown outdoors from a garden center or nursery, they are hardy – but ask!
Hardy mums are cheap and plentiful at this time of year - using them as table decorations is a great idea –Where can you buy floral centerpieces for a few dollars a pot –and plant them in the garden immediately afterwards – the sooner the better!
Florist's mums are larger, more interesting flower forms and a range of interesting colors and color combinations - but they are more expensive and aren’t reliably hardy. Florist’s mums are generally tender plants with larger flower heads, more exotic shapes -- and more expensive – but you for your party, you could go to a garden center and buy the more reliably hardy varieties. Get them into the ground after as fast as you can after your occasion – or winter them over indoors, and plant in the spring.
When you are growing your mums next year, pinch them back several pinches over the summer, beginning pinching in late May and ending pinching about mid-July. This will insure more flowers and a bushier plant next year that won’t require staking.

Hibiscus care
Q: You helped me in the past concerning bamboo plants. Now I have a question about my 5 ft Hibiscus plant that has been blooming beautifully for 12 years, indoor and outdoors. . My neighbor threw it out years ago. I rescued it. It is only out from July until September, so I don't know what kind it is. Now, it has not bloomed for 6 months. Should I call it a day and bury it? What is the life span of this long lived plant? Thank you for your help.
M

A: Have you ever repotted the plant? After a few years, they generally need it - not because of size, but because of soil depletion.
Hibiscus are heavy feeders - what are you feeding it? Hibiscus does enjoy a high phosphorus fertilizer (high middle number on the pack) which is usually recommended to stimulate bloom - but try a more balanced fertilizer (three numbers close to the same like 10-10-10), which will give the plant more of the trace elements.
I think you know that unless the plant is given a lot of direct winter sun, the blooms will be few and far between during the winter months. You will lose a few leaves and over the winter, even more will yellow - but unless the plant loses all the leaves, it should be OK, and will survive and leaf out in the spring. Don't overwater to try to correct yellowing leaves – it will only make matters worse!
Life span of a hibiscus? Hawaiian growers say about 10-15 years for most species - so don't bury it yet! Give it at least another year before the funeral.

Giant allium seeds and “garaging” perennials
Q: I have two questions for you. First of all my spring purple giant alliums are sitting on tall brown stems now. I noticed that the top part has little tiny seed pods where the flowers were. If I plant the seeds, will I get more alliums next spring? Second question, can I plant a beach type rose in a container and winter it over in an unheated garage? I'm looking for something I could put in a container and winter over as I am running out of room in my garden. Would some type of hydrangea work or even an ornamental grass of some type? Any suggestions.
Love your column in the Eagle Tribune.
D.V.

A: Yes, you can plant your allium seeds - the first year, sow the seeds thickly - they will develop tiny bulblets, like onion sets, which the following year, can be easily transplanted to more permanent locations. The seeds need a period of cold, - so don't collect seeds now and then plan to plant next year, unless you can hold them in a refrigerator under controlled conditions for about ten weeks.
Your second question on "garaging" plants for the winter: Plants are routinely kept in cold storage all winter by growers - but the temperature and humidity and watering is carefully controlled. Most perennials are able to easily endure freezing temps - but some not. Your success will depend on the careful care you are able to give the plants- in might be worth the work to plant them now and allow them to winter in the ground, transplanting to a more permanent place next spring.

Iris
Q: I was reading your column, and wondered if you might be able to answer a question. I have about twelve iris plants that for the last two years have not bloomed. Is there anything that you could recommend? They receive plenty of sun. Some of them are over 10 years old.
Thanks, S.

A: Are they bearded iris?
Then they probably need dividing - ten years is a long time to remain unattended. Iris rhizomes generally need dividing every 3-4 years, and crowding is one of the main reasons that they don't bloom. And if they have been in the same bed for over 10 years, the soil in the area is pretty well depleted!
You are in the very best time of the year to divide iris - do it from now til mid-September to take advantage of cooling temperatures and still have plenty of time for the roots to re-establish before winter-
Clumps should be divided and replanted in the same day! Dig clumps, trim out and discard diseased and old dry or smelly sections, divide, cutting leaves to about 6"-10" - and replant just under the surface of the soil - you should be able to brush your fingers across the soil when you finish planting and just feel the rhizome..
While the plants are out of the bed, you'll want to amend the soil with compost (avoid peat as it's too acid for irises) -And you might toss in a bit of bone meal, but mix it in well so the roots don't come in contact with it. Plant and water well, tamping the soil gently.
Mulch over the winter - and you should have some blooms this next spring and even more the following year! Let me know how it goes!

This week’s dirt…………………………………………………………
WEATHER ALERT!
Bring your houseplants indoors – the nights are getting cold!
Watch night temperatures – and bring in the tender houseplants that have been summering outdoors. Most houseplants are tropicals – and 50 degrees is about as low as they can tolerate without showing damage. And when you think of all the work you’ve put into those plants all year, you don’t want to lose ground with a single cold night. It’s always a temptation to leave them out for one more warm shower or one more sunny day – but it’s not worth it, unless you can carefully watch the falling temperatures and can carry them in each afternoon.
The ideal situation is to bring plants in before the heat goes on – dry heat in a house is a big change for plants that have enjoyed a summer in your yard or porch.

Sept 24 : Herbs under Lights, Systemic Insecticides, Saving Tuberous Begonias

Herbs under lights
Q: I currently have small yet healthy thyme, sage and oregano in 4" pots on my deck in full sun. My goal is to re-plant them together in one bigger pot to keep in the kitchen (which gets zero sun and is very dry) before the first frost. What should I do to ensure productive herbs indoors? I plan on purchasing a grow light but as a novice would appreciate your suggestions as to type, wattage, etc. Also the best soil.
I enjoy your feature in the Salem News and glean helpful tips every week.
Thank you! Sioux

A: Herbs certainly require more sunlight in the winter than we can give them, so you are wise to plan on using a grow light. And using grow lights, you can grow ANYWHERE, even under your sink! Roughly, for every hour of sunlight a plant requires, plant will need 2 hours under a grow light.
You can buy a unit (very attractive ) like the Aero Garden for your herbs , a self- contained unit with an adjustable light arm - looks great on the countertop, but beauty is expensive, about $150.
Or you could buy 4 ft. grow light tubes for about $10 each and use a simple metal reflector on an adjustable chain to control the distance of light to the top of the plant - cost for reflector about $20, but they aren’t glamorous and are a bit industrial-looking. But they are economical and you’ll get far more lighted space to grow plants - a 4 ft. tube will give about 4 feet X 8 inches of growing space.
When comparing cost of any fixtures, don't forget to figure the extra electricity you will use - the bulbs will be on about 12-16 hours a day. (Don't run the lights 24/7 - plants need to sleep, too!) Use a timer to save money and angst!
Keep a record of grow light tubes bought and hours used - bulbs grow weaker as they are used.
Light levels and balance can more accurately be varied if the herbs are in separate pots rather than grouped on one pot - keep the light source about 8-10 above the tallest leaves and turn plants regularly.
Plants grown under lights will need more water and more fertilizer through the winter months - and watch carefully for bugs!
Use sterile potting soil - it helps eliminate the bugs before they start!
Use only a fertilizers recommended for eatable plants and dilute and use it half strength. Any bug sprays you may have to use must also be for eatables - most bugs can be eliminated by a spray of water in the kitchen sink.
Give the plants a few weeks under lights before harvesting – then you can begin to pick a few leaves to use or dry - this careful pruning will keep the plants neat and compact. You probably don't have the room to grow and harvest bushels of herbs in your kitchen - but herb-growing in New England in February sure is fun to brag about! You might even have enough to give a friend-

Systemic Insecticides
Q: Many of the flower heads in my garden and window boxes are turning brown (coreopsis, marigolds and gerbera daisies). The plants themselves seem healthy. I don't know if it is a fungus or caused by insects. If I apply a systemic insecticide, will it affect bees and butterflies? Thanks!
Paul Allen, Jr.

A: It is generally felt that a systemic will not directly hurt a bee or butterfly - BUT the jury is still out on whether or not the larva of the butterfly might be affected since the larva eats the leaves. There is also some difference of opinion as to whether the honey in the hive, since it is gathered by the bee on a treated plant might also be affected because no one is quite sure as to what amount of toxic chemicals, in what concentration, would actually be available to these insects - this is based mainly on the systemic being applied to the root area and not the surface leaves..
It’s not always an easy choice: I personally only use systemics as a last resort on plants of value (not annuals and most often on the greenhouse tropicals, not in the garden), although I do love the results!!
I can't imagine what is affecting the gerbera and the marigolds and coreopsis - but I would guess that it's a fungus with all the wet and humid then cool weather we've had - and I would probably apply a fungicide from Safer's before turning to the systemic. Also, try keeping the plants as clean as possible by deadheading and removing any rotting material. Keep in mind that these are all annuals- and their season will soon be over!

Saving tuberous begonias
Q: My tuberous begonias are gorgeous this year. Is there any way to save them over the winter? Do they have a tuber that can be saved? As you can see I will hate to lose them. Thanks for any info you can give me.
J., Beverly

A: Yes, you can save the tubers from year to year - heaven knows they are getting expensive!
AND, when properly cared for, they will grow bigger and better each year!

Wait till a light frost destroys the plant - note I said "light" frost - you just want the surface foliage to die, not the whole tuber!
GENTLY dig the tuber from the ground - try not to bruise them! Rinse with a gentle stream from the hose and dry for about a week in a sunny, frost free place, where there are no rodents. Examine them carefully for rot - then allow them to dry further until the stems fall off.
Pack them away in either paper bags, one tuber to a bag so they don't touch - and won't spread disease....Or store them in a single layer in boxes of dry dirt or sand or peat - again, not touching. Some gardeners also dust them with an antifungal (sulfur) powder. Check the several times over the winter for any signs of rot - discard any rotting tubers!
Store in a cool, dry, dark, rodent-free place until next spring, when you can either start them indoors , - or wait a few more weeks when the soil begins to warm up, usually late May - and start them outdoors, directly in the garden.

This week’s dirt…………………………………………………………
Dirt: Weeds are thriving now as we go into fall – keep weeding, and you can remove not only the weed’s root – but also remove thousands and thousands of weed seeds which would germinate in your garden, this week, next month or next spring! Don’t give up weeding yet!