Tuesday, September 24, 2013

Fall Planting

I really do love this time of year.  It's still busy but not crazy busy like the vegetable garden and fruit orchards keep me from late July to early September.  I'm about ready to put the canner kettles away; the cold room shelves are full.  The cool, crisp nights lead to good sleeping weather. 

There are still things to do, though.  It's not too late to plant deciduous trees and perennials, although the latter will need some mulch for the winter.  My planting season has been cut short by an injured foot, but I did manage to move some tree seedlings from places they'd planted themselves but weren't welcome.  I can still always find room for these little treasures and sometimes I'm even lucky enough to just be able to let them grow where they land.

I also managed to remove the perennials I've used for containers throughout the summer and find places in the gardens for them.  I can feel better about tearing those containers apart at the end of the season when I know that I will be able to enjoy those plants in a new setting next year.

In North Dakota, fall is a great time to do planting.  The roots of the transplants need about six weeks of ground temperatures above 40 degrees to become well-established.  The ground temperatures cool much more slowly than air temperatures, so here we can generally plant through the month of September and oftentimes into early October.  Bulbs and dormant deciduous trees can be planted almost till the ground freezes.  Evergreen trees and shrubs should be planted by the end of September for them to be established well enough to survive the winter.

Fall transplants love the cooler temperatures - there is much less stress on the plant, allowing for better root development.   Often, moisture becomes more abundant again as we move into fall, and the cooler days and much cooler nights keep the moisture in the soil longer.  There are fewer diseases and pests to plague the tender transplants in fall.  While the plant may look a little worse for the wear this year (it may even look dead, but resist the urge to pull it out), it will reward with lush foliar growth next spring because of the vigorous root development that took place the preceding fall.

Another advantage of fall planting is the prices.  Many garden centers don't have the resources to overwinter plants, so they clearance them as fall approaches.  The later it gets in the fall, the lower the price goes.  Last year, I picked up several nice viburnums for $1.00 a piece - their original price was $19.99.  True, I had to really use my imagination to see the glory that could be coaxed out of their bedraggled little selves, but with a little trimming, some TLC, and fall planting, I had some beautiful new shrubs this year.

Just as it is with spring planting, adequate watering is critical.  The new transplants need to have a half to one inch of water each week right up until the ground freezes.  Then a three to four inch layer of mulch to protect the crown of the new plant from the freeze and thaw cycles of winter, and the scene should be set for a nice new planting to emerge in the spring.

Thursday, September 12, 2013

Tomatoes and Blights

You can definitely feel autumn in the air.  Mornings are crisp and cool, but not so cool that you can't be outside in your shirtsleeves  - or pajamas.  :)  The days are warm, but not too warm; and the nights are just perfection.  I love this time of year - as long as I don't think about what's right around the corner.

Fall is a busy time in the gardens.  The vegetable and fruit gardens are putting on their last hurrah.  One picking of tomatoes yielded 14 quarts of crushed tomatoes, 10 quarts of spaghetti sauce, 12 pints of garlic-basil-tomato sauce, 15 pints of salsa and 12 quarts of tomato soup.  Plus about 60 pounds of tomatoes given to friends and family.  I really hope next spring when I am too tender-hearted to throw away those extra tomato seedlings, someone reminds me of this season's excesses!

This over-achieving production is in spite of having some problems with tomato blight.  It appears that there may be a variety of blights attacking my tomato plants this year.  That's one of the dangers of a wet growing season, and of growing tomato varieties that aren't resistant to the various tomato diseases.  I am pretty attached to my Sheyenne and Cannonball tomatoes that were developed by North Dakota State University specifically for success in our North Dakota soils and growing conditions, so I am willing to take the risk on blights.  My brother, who was one of the recipients of some of the excess this year, said these tomatoes made the best tasting salsa he's ever had.  I happen to agree with him - they are firm, meaty tomatoes with a rich, tomato taste.  People who choose to grow heirloom varieties of tomatoes feel the same way about their tomatoes - the benefits of those varieties make them worth the extra trouble and the risk of blights. 

Early blight (internet photo)
Early blight is caused by the fungus Alternaria solani.  It comes from the soil and starts attacking the lower leaves of the tomato plant.  The first indication is usually some large, irregular brown spots which appear on the leaves and may have lighter, yellow spots in the center.  Eventually the entire leaf withers, dies and falls from the plant.  The fungus also infects the fruits, causing dry, leathery sunken spots near the stem end.   The dying off of the leaves makes the tomatoes prone to sunburn because they lack the protective foliage cover.   If this blight occurs early enough in the season, it can decrease the vigor of the plant and diminish production for the year.  (As you can see above, that was not a problem with my tomatoes this year.)

Septoria leaf blight, caused by the fungus Septoria lycopersici, occurs later in the growing season.  It makes its initial appearance as small yellowish-tan blotches on the leaves, with a dark halo around them.  They are smaller than the spots of early blight and are more regularly shaped.  They may have dark spots in the center of the lesions, called "fruiting bodies".  Infected leaves generally drop from the plant, again leaving the tomatoes susceptible to sunburn and rotting.  Spots may also appear on the stems and the blossoms, interfering with fruit production.

Late blight is caused by the pathogen Phytophthora infestans, which is classified as a "water mold"This pathogen attacks both tomatoes and potatoes.  In fact, its greatest claim to fame is the Irish potato famine during the 1840's.  It makes its appearance on tomatoes as regular or irregular oily looking spots.  A distinctive difference between late blight and other blights is that while early and Septoria blight attack the lower, older foliage first, late blight attacks the plant from the top down, affecting the youngest foliage first.  Late blight also more readily attacks the fruit, causing dark, mushy lesions, which may be more pronounced at the stem end of the tomato, but eventually cover the entire tomato.  The rotting tomato emits a distinctive, foul odor.  I've found that while you can trim out affected spots on tomatoes affected by other blights, tomatoes affected by late blight often have a nasty taste throughout the entire tomato.

As with all fungal infections, prevention is the best cure.  Good air circulation goes a long ways toward preventing fungal and mold diseases.  Remember those little seedlings I couldn't bear to throw away?  Well, at Wiese Acres, I have a limit to the space in my vegetable garden.  So, my tomatoes ended up a little more crowded than they should have been this year.  Strike one for my tomato plants.  Then, my tomato foliage went crazy and I didn't take time to properly prune the plants to keep them from completely overfilling the tomato cages.  Strike two.  Then, we had days and days of rain and even when it wasn't raining, we had cool, damp, gloomy weather.  Strike three!  And I had blights. 

Once any blight appears, if it is not extensive, you can gain some control by pinching off the affected  leaves and destroying them, then spraying the plant with a fungicide to prevent or at least slow further infection.  Chlorothalonil or mancozeb are effective against the blights, or for an organic solution, copper based sprays may provide some control.  Fungicides are more preventive than curative, so it's best to spray before any symptoms occur.  I'm a sort of "just in time" gardener, though, so it usually doesn't occur to me to spray fungicides before I have fungal infections. 

It will be critical to clean all the infected foliage off the garden and destroy it.  This debris definitely doesn't belong in the compost pile.  It will either be bagged and taken to the landfill, or it will be burned.  Next year, I will need to be careful to not plant any plants in the nightshade family (tomatoes, potatoes, eggplant, peppers) in the same area, as the spores of the fungus can overwinter in the soil.  I'll need to make sure that I don't overcrowd things next year, and if I irrigate, ideally, it can be done with a drip system.  If overhead irrigation is my only choice, it will need to be done early in the day when the leaves won't stay wet for extended periods.  I'll also check the nutrients in my soil.  Blights are much more likely to attack plants that are less vigorous and proper fertilization is one way to foster good, healthy plants.  I'll also place some mulch around the base of the plants as the mulch may stop any spores that may still be in the soil from splashing up onto the foliage and setting up housekeeping.

On a positive note, I did not have any blossom end rot.  I save my egg shells for several months leading up to planting time, crush them, and sprinkle a handfull in the bottom of the planting hole.  This supplies needed calcium for the tomato plants.  In addition to having the calcium available to them, though, they need to have even, consistent moisture to allow the calcium to be absorbed into the plant and fed to the tomatoes.  One or the other alone may not prevent blossom end rot, but the two together is just about a guaranteed prevention.

So, I've learned a few things to not do with tomatoes this year.  As I think about my aching feet and look at my reddish tinged hands, I can't help but think that throwing away those extra seedlings might just be the most important lesson, though.

Tuesday, September 10, 2013

Daylilies Diseases and Pests


Daylilies are usually pretty disease and pest free, if planting conditions allow for good drainage and the soil contains a good supply of organic matter.  The biggest problem I see when people tell me their daylilies aren’t “doing well” or aren’t flowering is that the daylily is planted too deep.  That crown should not be covered with more than one inch of soil.

But, just like sometimes even the toughest of us get sick, so sometimes do daylilies. 

Leaf streak (internet photo)
A common fungal disease of daylilies, especially the last couple years when we’ve had cool, wet weather, is Leaf Streak.  Leaf Streak is a fungal infection that causes yellowing along the central leaf vein, followed by brown streaking.  The yellowing usually begins at the tip of the leaf and follows the leaf downward towards the crown, leading to browning, drying out, and eventually death of the entire leaf. 
 

Prevention is the best cure, if possible.  When Mother Nature delivers the moisture, we don’t have much control over when or how it hits our daylily leaves. When we are delivering the water, we can be a bit more particular.  A drip system that delivers water directly to the soil without wetting the daylily leaves is the best way to irrigate.  If the only option is to water in a way that wets the leaves, it’s best to water in the morning when the sun and breeze will quickly dry the leaves.  When the daylily leaves are wet, whether from rain, irrigation, or dew, resist the urge to walk amongst them and admire their flowers and foliage.  The more we disturb the leaves when they are wet, the more opportunity we give fungi to set up housekeeping. 

Once the infection is evident, good housecleaning is essential.  Remove and destroy affected leaves.  These leaves do not belong in the compost pile – they should be bagged and put in the garbage.  Affected plants should be isolated from others if at all possible.  

It is difficult to “cure” a fungus once the symptoms appear, but spraying with a fungicide may slow development of the disease and prevent new growth from becoming infected with Leaf Streak.    Fungicides which have proven effective for Leaf Streak are thiophanate-methyl, mancozeb, chlorothalanil, and iprodione.   These are all marketed under various trade names, but if you look at the “active ingredient” on the label, one of these should be the top ingredient. 

The entire plant should be “doused” with the fungicide, upper and lower surfaces.  If your daylilies had Leaf Streak last year, it might be a good idea to prophylactically spray the new foliage right away in the spring, before any signs of disease.  Spraying every couple weeks during the growing season might be necessary to keep it under control.


Spring Sickness is considered a “mystery” disease – its cause is not known for sure, but it is definitely more prevalent in those areas where there are freeze / thaw cycles.  I’d never heard of this disease before the spring of 2012.  That spring, instead of my nice, bold, strappy daylily leaves, I started noticing that the leaves were growing sideways, twisting and turning every which way, sometimes ending up in a twisted mass in the center of the clump.  In addition, some of the leaves had jagged, brown edges. 

What in the world was happening?  I couldn’t see any signs of pests that might be causing the problem, no mechanical damage (e.g. no one had gotten close to them with the lawnmower or weed whacker), and no signs of fungal or bacterial infection.   So, I started doing some research and discovered “spring sickness”.  The winter of 2011 – 2012 was non-existent in North Dakota.  Most people were rejoicing in our winter with very few days below freezing and even 80 degree days in March, but we gardeners were already concerned about what this meant for our perennials.  The spring sickness in our daylilies confirmed that temperatures should just not be high enough to wear shorts in February in North Dakota. 

Spring sickness may also be caused by mites or some type of fungal infection, but in my daylilies, those not affected as severely, outgrew the problem by mid-summer and went on to bloom beautifully that year.  Those more severely deformed were just fine the spring of 2013, leading me to believe that it truly was our bizarre non-winter that was the culprit.

Bacterial soft rot is often caused by the bacteria Erwinia carotovor.  Symptoms are a soft, mushy crown and roots, often accompanied by a strong, foul odor.   Erwinia is a bacteria that is present in most soils but it doesn’t cause any problems until conditions are just right.  High temperatures, poor air circulation, poor drainage and improper fertilizing are friends of soft rot.   In these conditions, it spreads very rapidly and once soft rot becomes noticeable on the daylily, it might be too late to salvage.  If caught early enough, the daylily might be salvaged by digging it up, cutting out any affected parts, soaking the remaining part of the clump in a 10% bleach solution for 20 minutes, letting the cut surfaces dry, then re-planting in a well-drained area.

White mold is a crown rot caused by the fungus Sclerotium.  The crown of the daylily becomes covered with white, cottony looking growths.  Sometimes small, black seed-like growths are evident in the cottony growths.  There are no fungicides effective against sclerotia.  Treatment is to remove the daylily and the soil surrounding the plant for one foot beyond the root ball and one foot deep.  Both the daylily and the soil should be bagged and discarded.  Sclerotia lives in the soil for many years, so it is important not to compost any part of the plant or use the affected soil in other garden spots.
 
Rhizoctonia crown rot is another disease of daylilies that occurs in wet years, or in areas with poor drainage.  The crowns rot from the soil surface down towards and into the roots.  There is usually a dark, heavy growth on the crown of the daylily that almost looks like a piece of cloth or heavy felt wrapped around it.  Unfortunately, like the other crown rots, there is no treatment once the rot is established.  The only hope is to catch it soon enough that you can salvage some of the clump through the pruning and soaking method described for bacterial soft rot.

Pests of daylilies hardly bear talking about, in my opinion.  I have rarely, if ever, had much problem with insects.  Even slugs, those dirty little slimeballs, rarely do much damage to daylilies.  Cutworms, cucumber beetles, Japanese beetles, grasshoppers and bulb mites may cause some periodic damage, but usually not of much significance. 

Spider mites are the most common pest of daylilies, especially in hot, dry weather.  Spider mites cause yellowing of the leaves, sometimes with tiny brown spots amongst the yellow showing where the mite began sucking the clorophyll from the leaves.  The webbing is sometimes visible, especially on the undersides of the foliage, and you may even see the mites moving in the webbing.  Usually a strong spray from the garden hose or spraying with an insecticidal soap will do the trick. 

Thrips may infest daylilies and cause streaking on the leaves and buds.  They often cause deformities in the petals, leading to an unsightly flower.    There is a specific aphid that feeds only on daylilies and isn’t controlled as easily by a hosing off with plain water as most aphids, because they get deep into the folds of the foliage.  Both thrips and aphids are best controlled by a systemic insecticide if the infestation is severe.  A common systemic insecticide, dicofol, marketed as Kelthane, Hilfol, or Acarin should not be used on daylilies, as it can damage the plant.  Other systemic insecticides should be safe for use, but please keep in mind that systemic insecticides are not selective to thrips or aphids – if a butterfly or bee stops to sip the nectar from your daylilies, it will kill them, too.  In most cases, the pest problems are not severe enough to warrant these “big guns”, in my opinion.

It is really hard to find a more carefree plant than a daylily and they give so much beauty and diversity to the garden, it’s hard to go wrong with them.