This week in the garden. There have been questions about why my vine crops like cucumbers and summer squash are blooming but not setting fruit. Vine crops have male and female flowers and only the female flower produces fruit after being pollinated. The first flush of flowers is usually male then followed by female flowers. If you look at the flower, the female flower has a little fruit behind the blossom and the male flowers have a straight stem connected to the vine.
Some of the fruits may have a rotting end on the fruit. Most likely this is caused by improper fertilization, particularly in vine crops. This should cure itself in time.
Now let’s talk about cross-pollination between like a pumpkin and a cucumber. The answer is no. The plants have to be in the same Genus to cross-pollinate. For instance, different varieties of cucumbers will pollinate together as will squash. I planted yellow and green zucchini and got a few striped fruits, which was still good. Some varieties of melons will cross-pollinate among varieties. The odd fruit will show especially if you save the seeds from the fruit and plant the seeds next year or if a volunteer plant germinates and grows producing the odd fruit. That is why you buy new seeds every year or use up what is left from last year.
If your grass tips turn brown after mowing, this is most likely due to a dull or chipped mower blade. Sometimes mowing during the heat of the day causes the cut tip to dry out quickly.
Black spots on rose leaves is a fungus that spreads rapidly among certain varieties of roses. Use an ornamental fungicide to protect against the spread of this fungus. There are rose varieties resistant to this fungus.
Iron chlorosis is showing on some shrubs and trees. Some varieties show yellowing leaves with green margins. Our high soil pH sometimes ties up the iron (and magnesium) in our soils especially when the soil is dry. Treatment of liquid iron to the foliage or soil helps. Silver and Amur maples are particularly susceptible to this condition.
It is still not too late to plant or replace most vegetables in the garden due to hail or insect damage. Hopefully, we have at least 100 days till frost.