Despite our best efforts, sometimes bad things happen to our prized tomato plants.  Here's a list of tomato problems and solutions that I've compiled from a variety of sources including the University of California Cooperative Extension, California Department of Agriculture, United States Department of Agriculture, Rodale Press, University of Wisconsin Cooperative Extension, and Washington State Cooperative Extension.
 
YOUNG PLANTS

Symptom:  Wilting and falling over at soil line.
Problem:   Damping off fungus.
Solution:  Use clean soil.  Provide warm, well-drained seedbeds, control excess moisture.

Symptom:  Cut off near soil line.
Problem:  Cutworms or darkling ground beetles.
Solution:  Protect  transplants  with can or paper tubes reaching one inch below  and above soil surface.   Spray with Bacillus thuringiensis (Bt).  At end of season, clean the area to discourage the cutworm from laying its eggs.
 
GENERAL PLANT GROWTH

Symptom:  Tops become weak,  pale, dwarfed, wilt easily, and die prematurely.  Yield is lessened.  Swelling on roots becoming distorted, enlarged, and decayed.
Problem:  Root knot nematode.
Solution:  Plant resistant varieties.   Interplant with marigolds (especially dwarfs) or where marigolds were grown and dug into the soil.
 
Symptom:  Sudden wilting of plant and rapid rotting of roots.
Problem:  Phytophthora  root  rot brought on by excessive watering  and  lack  of drainage.
Solution:  Correct irrigation techniques.
 
Symptom:   Deformed growth or wilt.
Problem:  Numerous  insects sucking sap.   Aphids found on undersides of  leaves  or clustered on new growth.   Whitefly larvae on underside of leaves,  adults fly up when foliage is disturbed.
Solution:  A few insects won't hurt production.  Crush them onto leaves or stem.  Spray with soapy water.  Natural enemies of aphids include ladybug larvae and adults, syrphid fly larvae, lacewing larvae, and parasitic wasps.
 
Symptom:  Slow growth. Leaves paling from top of plant down.  Leaves small and thin, with purple veins.    Stems yellow and rigid.  Flower buds yellow and drop off.
Problem:  Nitrogen deficiency.
Solution:  Apply nitrogen and compost.
 
Symptom:  Slow growth.   Plants tinged purple.   Leaves small and fibrous.   Delayed fruit set.
Problem:  Phosphorous deficiency. 
Solution:  Apply bone meal at planting time, and sidedress six weeks later.
 
Symptom:  Brittle young leaves that curl up and turn yellow away from stems.   Green border on yellowed leaves.
Problem:  Magnesium deficiency.
Solution:  Incorporate dolomitic limestone or a handful of Epsom salts at planting time.
 
Symptom:  Blackened  areas  at growing tip of stunted stem.   Terminal shoots  curl, yellow, and die.
Problem:   Boron deficiency.
Solution:  Apply one teaspoon of borax around base of plant and water in.
 
Symptom:   Yellowed leaves with green veins.
Problem:   Iron deficiency.
Solution:  Add acidic supplement such as leaf mold or manure.
 
Symptom:  Stunted shoot growth,  poor root development, bluish green foliage, leaves flabby and curled upward.  Few or no blossoms.
Problem:  Copper deficiency.
Solution:  Apply manure.
 
Symptom:  Small,  narrow  leaves colored yellow between veins and mottled with  dead areas.  Stems may crack.
Problem:  Zinc deficiency.
Solution:  Apply manure.
 
Symptom:  Very slow growth.   Yellowed areas between veins on leaves.  Few blos­soms, no fruit.
Problem:  Manganese deficiency.
Solution:  Apply manure.
 
LEAVES

Symptom:  Roll upward and are firm and leathery,  but with no yellowing or stunting.  Leaves on the sunny side of staked plants may often curl,  while those  on the shady side do not.
Problem:  Common growth, no harm to plant development or fruit production.  Too much leaf pruning, sucker removal, or overly wet soil may pro­mote.
Solution:  Plant on well-drained soil.   Do not cultivate deeply near the plants, and avoid extremely close pruning.
 
Symptom:  Roll upward and twist, become stiff and leathery, yellowed, stunted. Veins on underside turn purple.
Problem:  Curly top, western yellow blight.  Transmitted by leafhopper from weeds.
Solution:  Use resistant varieties.  Destroy infected plants. 
 
Symptom:  Yellow and green mottling,  crinkled,  and smaller than normal, shoestring appearance.
Problem:  Mosaic  viruses.   Transmitted from weeds and  flowers,  aphids,  cucumber beetles.
Solution:  Wash  hands with soap and water before handling plants.   Do not smoke  or handle  tobacco  before  or while handling  plants.   Remove  and  destroy infected plants.
 
Symptom:  Numerous  small dark brown circular spots on young leaves, becoming bronzed and withered;  older foliage is yellowed.   Dark brown spots or streaks on stems near tips.
Problem:  Spotted wilt.  Spread by thrips from weeds and ornamentals.
Solution:  Keep separate from vulnerable vegetables like lettuce,  celery,  spinach, peppers, and potatoes. 
 
Symptom:  Yellowing,  wilting,  dying  of lower leaves progressively up  the  plant.  Initially,  often  affects only one side of the plant.   Brown streaks  in tissue  of  lower  stem when split lengthwise.   Produce few  fruit  which usually decay and drop before ripening.
Problem:  Verticillium or fusarium wilts.
Solution:  Plant  resistant  varieties.   Use clean  soil.   Avoid  areas  previously planted with toma­toes, peppers, eggplant, potatoes, or cucurbits.  Destroy infected plants.
 
Symptom:  Distorted,  cupped,  or curled,  ragged at edges, curved downward.  Light-colored veins appear parallel.
Problem:  Hormone-type herbicides.
Solution:  Use extreme care when using herbicides.   Plants may outgrow damage if given good cultural care.
 
Symptom:  Irregular greenish-black water-soaked patches on older leaves which enlarge and may show a white, downy growth on surface.  Fruits develop gray, green spot which becomes brown and wrinkled or corrugated; may become mushy.
Problem:  Late blight fungus.
Solution:  Prevalent in mild, moist weather.  Hot, dry weather will slow or stop advance of disease.
 
Symptom:  Dark areas of dead tissue surrounded by yellow on oldest leaves.
Problem:  Anthracnose, a soil-borne fungus disease.
Solution:  Avoid  handling wet plants or planting in poorly-drained soil.   Rotate to new  soil each year.   Remove and destroy infected plants or  plant  parts after harvest.
 
Symptom:  Many  tiny round holes,  leaves may be so riddled that they turn brown and wilt.
Problem:  Flea beetles.
Solution:  A  few holes are not damaging.   Most damage occurs during the first  warm weather of spring, when plants are small.  Apply garlic spray.
 
Symptom:  Eaten or chewed, partially or entirely.
Problem:  Hornworm.
Solution:  If  the  worm is carrying white pupae,  let it be -- it's the victim  of  a parasitic  braconid  wasp  and should be left to nurture a  new  brood  of beneficials.   Remove worms by hand and destroy (sprinkling water on plant will make them wriggle, making them more visible and easy to pick).  Spray with Bt.  Release  trichogramma wasps.  
 
Symptom:  Greasy appearance becoming bronzed and stippled, webbing and "moving dust" on  undersides of leaves or in leaf axils.   Plant appears to dry out from the ground up.  Leaves turn brown and paper-like but do not wilt.
Problem:  Mites.
Solution:  Thrive in hot,  dry weather.  Wash  down plant, especially undersides of leaves.  Use garden  sulfur according to label directions.
 
BLOSSOMS

Symptom:  Lush foliage, but no blossoms and few fruit.
Problem:  Too much nitrogen.
Solution:  Incorporate a balanced fertilizer at planting time.   Do  not  feed  more nitrogen during growing season.
 
Symptom:  Blossom drop.
Problem:  Plant  is  stressed  due to cool night temperatures (below  58 degrees)  or  high daytime temperatures (over 90 degrees),  unusually heavy fruit set, lack of moisture,  poor soil fertility,  too much shade,  certain diseases,  exces­sive nitrogen  ferti­lizer,  insufficient potassium or phosphorous,  or an aphid infestation.
Solution:  Plant in full sun.   Large-sized fruit varieties are very susceptible where summers are hot and  dry.  Choose varieties which produce  small or medium-sized fruits.  Cherry  tomatoes  tolerate  cooler weather and set fruit better  when  air temperatures are in the low 50's.  Blossom set will resume approximately seven  to ten days after temperatures return to cooler  levels.   Readjust irrigation schedule.  Natural enemies of aphids include ladybug larvae and adults, syrphid fly larvae, lacewing larvae, and parasitic wasps.
 
FRUIT

Symptom:  Light-colored cloudy spots with pithy or corky areas just below the skin.
Problem:  Stink bug punctures.
Solution:  Remove  by hand and destroy.   Spray with insecticidal  soap.   Keep  down weedy areas if bugs have been persistent.  Plant smaller sections of crop, rather than large areas.
 
Symptom:  Hole at stem end and fruit hollowed out.
Problem:   Tomato fruitworm.
Solution:  Remove  by  hand  and destroy.   Spray with Bt or  onion/garlic  solution.  Release trichogramma wasps.  After harvest, turn soil to kill pupae.
 
Symptom:  Large holes or completely hollowed out.
Problem:   Slugs.
Solution:  Stake  tomatoes and place mulch or boards under fruit to get them off  the soil.  Harvest frequently.
 
Symptom:  Hollow fruit.
Problem:  Poor pollination caused by low light (dark,  cloudy days), too much nitro­gen,  heavy rainfall,  temperatures that are too high (over 90 degrees) or too low (below 58 degrees), or too much hormone fruit-set spray. 
Solution:  Set  tomatoes  out later in season and modify  environment  with  hotcaps.  Shade in hot weather.  Use less fruit-set spray.
 
Symptom:  Cracks--concentric circles around stem or in lines radiating from center.
Problem:  Sudden, rapid growth during high temperatures (over 90 degrees) and high rain­fall or  heavy irrigation,  especially after a dry spell.   Ripening fruit  and fruit exposed to the sun are most affected.
Solution:  Plant  less-susceptible  varieties.   Keep soil evenly moist  with  proper watering  techniques and mulches.   Do not remove leaves from plants.   Do not irrigate just before harvest.
 
Symptom:  Black mold along growth cracks.
Problem:  Damaged, cracked tissue developing under warm, moist conditions.
Solution:  Prevent fruit cracking (see above).  Handle fruit carefully.
 
Symptom:  Misshapen fruit but with no scars.
Problem:  Inadequate moisture, fruit confined in foliage.
Solution:  Water deeply and more frequently,  especially during hot spells.   Provide trellising, free fruits from binding.
 
Symptom:  Catfacing -- misshapen,  puckered,  swollen areas; cavities lined with scar tissue.    
Problem:  Incomplete pollination due to 1) weather being too cool or hot, 2) bees not being available,  or  3) overhead irrigation during blossoming that makes blossom cling to itself, resulting in abnormal shaping of the fruit.  Common on early fruit of varieties that produce large-size fruit. 
Solution:  Plant less-susceptible varieties,  including those bearing smaller  fruit.  Encourage bee activity.  Irrigate under foliage.
 
Symptom:  Circular sunken spots on skin which enlarge and darken.
Problem:  Anthracnose.
Solution: Plant  in well-drained soil.   Destroy plants and fruits (don’t compost).
 
Symptom:  Blossom-end  rot – water-soaked  area  on blossom end  which  darkens  and becomes larger, sun­ken, and leathery.
Problem:  Related  to lack of calcium due to  lack of water when plants  have  grown rapidly  during the early part of the season and then are subjected to hot dry  weather when the fruits are in an early stage of  development.   More severe in sandy soils and soils with a high salt content.
Solution:  Plant  less-susceptible  varieties.   Refrain from planting in  very  cool soils.   Calcium is not available to plants at a low soil pH, so incorpor­ate dolomitic limestone at time of transplanting.   The finer the grade of limestone, the faster it breaks down in the soil, and the sooner it raises the  pH and enables the calcium to be utilized.   Keep soil  evenly  moist with  more thorough irrigation.   Stake tomatoes or mulch beneath them  to get fruit off ground.
 
Symptom:  Brown, slightly sunken spots which enlarge, dar­ken, and break open.
Problem:  Soil rot fungus  where fruit are allowed to lie on the soil or are repeat­edly splashed by rain or over­head irrigation.
Solution:  Plant in well-drained soil, stake tomatoes, and mulch beneath them.
 
Symptom:  White or yellow patches on parts of green or ripening fruit which face the sun;  become  blisterlike and form large,  flattened,  grayish-white areas with a dry paperlike surface.
Problem:  Sunscald,  most  frequent during hot dry weather and on plants which  have lost foliage from pruning or disease.
Solution:  Some  varieties  with  little foliage are more tender  and  sunscald  more easily.   Do not remove leaves from plants.  Where fruits are exposed, put a light covering over the clusters to diffuse the direct sunlight.
 

     Tomatoes are blossoming and setting fruit, as are squash and beans and peppers, persimmons, tangerines, oranges and grapefruits; plums and nectarines and peaches and figs are ripening.  The boysenberries are finishing.  The short-fruit (1 inch) mulberries are done fruiting, and I’ve pruned back the branches, but the longer-fruit (3 inch) Pakistan are just turning color. 
 
Tomatoes
     Plants are big and bushy, filling their cages, which proves that they have more than enough nitrogen in the soil.  But they’re also loaded with blossoms and some already-set fruit – especially the cherry tomatoes – so they also have enough phosphorus and potash and micronutrients; and have been well-watered to keep them growing well.
     As our hot temperatures start being consistent, be sure to keep tabs on your deep watering of all of your vegetables, especially for tomatoes.  If you allow too many days between watering deeply, the plant roots will be unable to satisfy the vigorous growth of the plant, and the outermost cells of the plant – the fruits – will die back, creating the dark leathery “blossom end rot”.  This is your cue to water deeply immediately.  You should also remove the affected fruit, so the plant’s energy can transfer to another fruit to ripen it instead.  If the affected fruit is nearly ripe, just cut off the leathery part and eat the still-good part.
 
Squash
     My first batch of yellow-crookneck squash continues to bear, although some of the fruits shrivel and die because they weren’t pollinated; but almost-too-many more get to harvestable size so I have more than enough to eat and supply our neighbors.  Which is good, because my second batch of squash plants that I’d seeded when the first batch started bearing are almost ready to start bearing themselves.  Next year, I’ll allow 3 weeks instead of 2 weeks between new sets of seedings so I don’t have this too-much-squash overlap. 
 
Grapes
     My grape vines that I’d rooted from cuttings 2 years ago are blossoming and setting fruit, so of course I’m visiting them every day and urging them on.  I’ve been amazed at how much new foliage has developed and consider this a two-fold blessing – it shades the grape clusters from too much direct sun, and (perhaps more importantly) shields them from marauding birds and squirrels and whatever other critters might be interested. 
     I’m assuming that if they can’t see the fruit, they won’t know it’s there – we’ll see whether this actually bears out.
     Expect the individual grapes to be smaller than any that you purchase commercially, since those are treated with hormones to make them larger and more marketable.
  I remember reading a tip years ago that recommended trimming out half of the fruit clusters so the remaining berries could utilize all the plant’s energy to grow even larger.  I haven’t had to do this yet because only about half of the blossoms have set fruit, and the berries are pretty well spread out, with lots of space between each one. 
     So I also won’t have to deal with any rot setting in because the little grapes still have so much “breathing” space around them. And, I don’t overhead water so theoretically no moisture will settle between the berries to cause rot problems.
     I’ve debated whether to trim some of the foliage stringers so the energy will redirect back into the fruit clusters.  I’ll remove some of the longer vines, especially those that I’ll want to remove later in the year in anticipation of harder pruning back.
     Lastly, hold back on watering your grapes for the last 2-3 weeks before harvesting the clusters, so the sweet flavors are concentrated instead of "watered down" due to continued irrigation.

More June Tips