P:My rhododendron leaves started to turn yellow and their tips turned brown. There are also brown spots on the leaves that have not discolored. My rhododendron grows in a secluded place, and after noticing all the changes, I replanted it, but to no avail.
O:Yellowing of rhododendron leaves indicates nitrogen deficiency in the substrate. Plants mulched with bark or sawdust, apart from fertilizers intended for rhododendrons, should be additionally supplied with nitrogen in the form of ammonium sulphate. This fertilizer is used from the end ofAprilto the middle ofAugustin 3-4 doses.The soil should be moist before spreading the fertilizer. Also suitable for feeding shrubs are cattle manure in a dilution of 1:10-1: 15, used from mid-April to the end of June at two-week intervals. And in this case, the plants should be watered beforehand. The slurry should be poured carefully, without pouring it onto the leaves.
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Rhododendron flower is one of the most beautiful that we can easily grow ourselves (Image: Fotolia.com) |
Brown spots on the leaves indicate a very widespread fungal disease called leaf spot. It is caused by variousspecies fungiFalling leaves should be picked up and burned, and the bush should be sprayed alternately every 10-14 days with the following preparations: Benazol 50 WP, Dithane M-45, Euparen 50 WP or their equivalents.You can strengthenplantsby also using sprays based on naturalgarlicorgrapefruit , which reduce the growth of fungi .
P:I am asking for advice on a pond. I have a pond in the garden on the south side, not shaded, but unfortunately there is always a problem with keeping the water clean. There is a filter in the pond, we also use anti-algae measures, but despite this, the problem of contaminated water arises every year. We replace it more often than recommended so that you can see the fish. So I am asking for tips on what to do to keep the water in the pond clean?
O:Water quality depends on pH, nitrogen content and hardness. For aquatic plants and fish, the most favorable reaction is neutral (pH 7). Special indicators are used to measurepHvalues, which when added to water change its color. By comparing the obtained color with the color scale, the result is read.The most reliable measurement of the water pH is obtained by carrying out the test just before noon. Special preparations are used to equalize the pH of the water, e.g.AquacidorAqualkalIf the pH is too high, acid peat may also help. The burlap sack with peat is immersed in water; released humic acids slightly lower the pH of the water and significantly reduce the growth of algae.
Nitrogen compounds ( nitrites ,nitratesandcompounds ammonium ) appear in the water as a result of the decomposition oforganic substances (plant and animal remains, fish excrements, fish food remains). This phenomenon is exacerbated by an insufficient amount of oxygen in the water and an elevated pH. Permissible content ofammoniais 0.05 mg / l,nitrite- 1.0 mg / l, andnitrate - 50 mg / l. To test the presence of these compounds, there are special kits that also contain measures to regulate their content in water.
Water hardness is determined by the content of calcium and magnesium s alts and carbonates. It is determined using special tests and color reagents, and is determined in the so-calledGerman degrees(1 deg. Is 10 mg CaO per liter of water). For aquatic organisms, the most advantageous is the average water hardness, ie 8-14 degrees Celsius. When the water is too soft, it is enough to add natural limestone or dolomite to the substrate in the pond. Water hardness can be lowered by installing only special filters with the so-calledcationitem
When the biological balance of the water is disturbed, the algae invasion is immediate. When buyingagents chemicaldestroying these organisms, choose those that simultaneously bind the releasedhydrogen sulphideUsing these measures, we cannot abandon the mechanical purification of water with a mesh, and the installed filter should contain activated carbon.
Ponds in sunny places should be shaded with a mesh, the so-called with a shade line, or 1/3 of the pond surface must be covered with vegetation with floating leaves. In summer, at high temperatures, at nightoxygenatewater with, for example,fountainsExcessive amount of fish should be caught, and the doses of food for them must be determined in such a way so that it is completely eaten and does not sink to the bottom.
