How to revive a banksia with dried leaves?

[amichaelmedia]

Plants have started to drop the dried out leaves. After I changed the watering schedule and a round of fertilizer I'm not sure if they are improving or not 

Is this still recovering from lack or water or something else 

[Jason]

Hi @amichaelmedia,

Could you please tell us more about the growing conditions? Where are you based? What is your soil like? How much have you been watering?

The guide How to diagnose a sick plant by @Noelle might have some helpful advice for you.

Thanks,

Jason

[amichaelmedia]

Ocean side town in Victoria (3226)

Clay base, Sandy loam and 1yr old mulch on top. 

Dry Fertilized on schedule. started watering (last month) once I saw leaves were discolored. Had a wet summer here so no need to water before then 

[Jason]

Thanks so much for the extra information @amichaelmedia.

Let me tag a couple of gardening experts in @Noelle and @mich1972 to share their thoughts on your banksia. 

Jason

[mich1972]

Good morning @amichaelmedia May I ask what type of fertiliser you have been using ? I wondered if they have been burnt by it. Or possibly overwatered. Not so sure. I’ll wait for Noelle to have a look 🌿😊

[Noelle]

Hi @amichaelmedia 

The appearance of the banksia leaves, in my opinion, looks to have been caused by either too much (most likely) or too little water. You mentioned a clay subsoil - did you dig into the clay when planting?  If so, you may have created sumps which fill and hold moisture for long periods after heavy rainfall. Even if you didn't dig into the clay, the sandy loam (depending on its depth) sitting on top of the clay may not drain well, thus the roots are remaining very wet for extended periods.

The effects of "wet feet" will be most noticeable on the ends of branches and shoots, as indicated by your photos. I don't think it is fertiliser-related - that would show up throughout the plant rather than just on terminal leaves.

Aerating the soil and perhaps deflecting drainage from the paving away from that garden bed may assist in resolving the situation.

[mich1972]

Brilliant !!! Thanks for that @Noelle 😃

[MitchellMc]

Hi @amichaelmedia,

Anytime someone mentions a clay base and the possibility of excess water, then it's highly likely that the dying leaves are due to the plant having wet roots. @Noelle has covered that, and I'd agree that would be the first thing to investigate. It's quite easy to mistake "dried out" leaves for dying leaves. An over/under-watered plant can exhibit quite similar signs.

After it rains or you've watered, how long does the soil 10 cm down stay wet? If the soil hasn't begun to dry out within a few days and is still saturated, this is likely a drainage issue. For now, only water once the soil has dried out 10 cm down or you've had a period of very hot weather. Given the plants are native and established, unless it hasn't rained for at least a week, they are more than capable of finding their own moisture.

Please let us know if you have any questions.

Mitchell