Many Annuals Affected by This Season’s Weather Extremes

By Pat Bellrose

Heavy rain, way below normal temperatures and  now extreme prolonged heat!

Each year gives us new challenges growing annuals, But this year WOW!

If you planted early you probably are experiencing  some issues.  If you have planted late or have not planted yet  your plants are experiencing a different set of issues.

So far I have gotten calls on Petunias, vinca and begonias.  Petunias like the cool weather we had but not all the rain.  Vinca likes it hot and dry so it is starting to have all kinds of issues. I started writing this on Friday and  Monday and Tuesday  of this week I got three calls about plants not surviving the heat.

1.      Heat stress is bad this year because it is occurring so early in the season before the annuals and newly transplanted perennials and shrubs have a chance to root down.  Normally I stress deep watering but because your new transplants do not have deep roots you should be doing multiple  moderate watering.  This may mean watering twice a day in these 98 degree days.  I saw a beautiful bed of Lantanas from 4 inch pots just frying in an irrigated bed.  Again you may need to hand water or over ride your irrigation system to give some moisture during the afternoon hours.

2.     For petunias (waves)  after this hot spell is over I suggest a liquid feed with a urea-based soluble fertilizer.

3.     For Vinca the cold and wet took its toll.  The good news is they love this heat.  Watch for over watering even in the heat because of their weakened root system.  Once it cools to normal temperatures  fertilize with a urea-based soluble fertilizer.

4.     Begonias: I have had only one  call, but if you remember from last year; begonias just sat there in June and did not add any new growth.  A lot of different reason were suggested.  The beds I did soil tests on were all low in nitrogen.  We normally do not think of begonias as high nitrogen plants but with all the rain a lot of nitrogen was leached out of the soil and now with the heat ammonium is vaporizing out of the soil.

Check those irrigation timers  are they really doing what the annuals need.  In doubt about nutrition run a soil test is $25.00 well spent.

Pat Bellrose owns and operates Fahr Greenhouses, 18944 St. Albans Rd. in Wildwood. He wrote this article for retail nursery customers and we have modified it slightly for home gardeners.